I think a key piece of information is, did your relationship with your wife pre-date the end of your first marriage? Because if so, I'm afraid neither you nor your wife have a leg to stand on. You simply cannot expect a child, particularly a 17 year-old who is old enough to understand what happened, to accept the presence of someone who contributed to the demise of their family. It's natural that she wouldn't want to see her and that she would have complicated feelings towards you as well.

If there wasn't an affair, then that's another story that requires a different approach. 

So the elephant in the room question.  Did you have a relationship with your current wife before your other relationship was over?  If so, you have to understand that your Wife is bearing not only her share of the blame from your EX and daughter.. but she also carries YOUR blame from your daughter.. because kids tend to do that.. they may not be able to "hate" their bio parent.. so they transfer that resentment totally onto the new spouse.  If that is the case.. then it may be tough to hold the line on what your wife might want.. because it will be hard to ever get your daughter to get past the feelings of resentment towards your wife.. not unless you are willing to truly fall on your sword about things.. and make her understand that as an adult that it's difficult.. but everyone has a right to be happy.. including you.. and that staying with her mom wasn't an option...no matter who you had met.

But.. to the issue you have at hand.

I do think your daughter has the right to ask that your wife not attend.  Clearly it causes drama and conflict and as your wife, I would not want to go where I was not wanted.. I mean.. she isn't going because she cares for your daughter or the outcome of the game is she? 

BUT... YOU have the option to not attend.. or not attend as often if your wife isn't welcome.. that's the trade off for your daughter isn't it... well.. my wife is not welcome.. so I won't be coming to as many games.. 

I wouldn't necessarily agree that you are disrespecting your marriage by attending the sporting events of your bio child.. a child she doesn't have a connection with.. alone.  ONLY if you are spending too much time away from your wife does that come into play..  I think your wife is being a bit extra difficult about this situation.. her best path is to disengage and allow you to have some relationship with your child.. evne if it doesn't include her.. but YOU have to decide to hold your child to being respectful to your wife when they ARE together.. and this will tee up future issues like her marriage or graduations.. where she may not want to share them with your wife.. but want you present.. so you may need to decide how to navigate that.

To be clear.. some people decide to go separate.. I would allow my DH to see his kids without me.. but he would NOT go to a BM event without me.. but he hates her.. so...haha.

Sure a sports auditorium at the school is technically a public space.. they can't "keep her out".. but it feels like she is going to make a point.. not to support your daughter or to support the team in general.. for THAT reason.. your wife is being the AH for going when she has been asked not to.  If the reason was that you spend 4 nights a week.. and she wants to spend time with you.. that's a different motivation.. but I'm guessing it's kind of that she wants to go more because she is being told NO.. and for that.. she is a full participant in the drama.   and.. again.. if you both were dating and knew you were married.. well.. this is some of the unfortunate fallout you can expect from that.. not everyone is going to be all Buckingham palace and stand beside the woman who was having a public affair while your now deceased mother was alive. 

Idk, affair or no, what are the chances this marriage survives if the wife is never allowed anywhere the daughter is? We don't know that it was an affair. But, even if it was, OP has to face the consequences. He will never make everyone happy so where does he draw the line? Today it's sports games, what about weddings, graduations, Christmas...is he going to put his wife in some kind of second-class spouse role and give SD and his ex control over when his wife can accompany him to things? If it was an affair, he has already done it. No amount of catering will allow him to take it back. Does he try to straddle the middle of the fence or does he go all-in on his marriage?

Also, all of that assumes it was an affair. If it wasn't, and OP is allowing his daughter and ex to act that way, I feel sorry for his wife.

ETA if it was an affair, he has already betrayed one wife. Betraying another (or treating her like a second class spouse) is not likely to make his life any less of a mess.

You must talk with your DW.  Come to some understanding,  She has to know that it's not going to be a big happy family.  There is more important events coming up.  Graduation, holidays wedding, GK.  How are you going to handle there events .  What's happening with holidays now ? What was Christmas like? 
You made your choice when you married your DW. If you want this  marrage to last,  you must go along with DW.  After everything you can not disrespect her,

Married Your Affair Partner or Not.

I think we are all in close agreement in our answers and suggestions being dependent on this big question. Rather than provide suggestions that cover ALL scenarios, Ill wait for the answer to this question.

Now she is saying enough is enough and I'm disrespecting her and our marriage by having her stay away from my daughters school events.

You should have never tolerated this crap from your X and the spawn. Not at all.

Your wife should be at your side. More importantly, you should be at hers. If your XW accosts your wife at sporting events, your wife should agressively end that threat.  That you tolerate this crap from your noxious failed family spawn and your failed family mistake of a breeding partner is far more than your DW should tolerate.

Man up.  Grow some balls. Be your wife's husband and stop sniffing the asses of your noxious manipulative spawn and her idiot mother.

IMHO of course.

You and your DW should start recording the XW/BM when she verbally assaults your wife at your DD's sporting events.  Better yet, get a go pro for each of you ostensibly to record your DD's sporting events.  Reality is, get your idiot XW on camera with her bullshit and then bare her ass legally and publically. 

As for your DD, her whining and crying about stress with SM is at her events, etc, etc, etc is pure PAS manipulative kiss her mothers ass bullshit.  Your daughter is a manipulative POS kid.  Not surprising considering that her mother is a PASing POS and you are not setting and enforcing standards of behavior or standards of perfomance for either of them and you are not being a true equity life partner to your own wife.  Your daughter is not a young child. She is a young adult and your failure to put your foot up her ass is in large part the problem.  Stop sniffing her ass and start kicking it. Figuratively of course.

Stop tolerating the POS people who are killing  your marriage. For clarity, the POS people are  your daughter and her idiot mother.  You are on the cusp of being one of the POS people ruining your marriage. Don't do that.

Grrrrr.

On the "did you marry your mistress" topic. As a man whose XW was a cavern crotched serially adulterous skank whore, I get that may be why your kid and your XW are who and what they are. However, your DW still must have your absolute loyalty and support at all costs.  Even if that means the loss of a close relationship with your kid.  If you did cheat and marry your cheat partner, that is on you. Not your DW.

If  you cheated, this also is not on your XW and your DD.  You have to fix this for your wife and your marriage, take the beatings from your wife, you XW, and your kid, and man up.  While defending your mate and your marriage.

As most members here, I think there a pieces of this story missing. I really can't reply fully w/out that info. 

is there a reason for your daughter's dislike of your wife? was there an affair? is there a mutual dislike between daughter and new wife? and lastly, why exactly does your wife want to be there, is it to pee on your leg in a manner of speaking? 

I would suggest finding a mutally acceptable way for your wife and daughter to work on their relationship with the aim of being able to at least tolerate and respect each other. In the mean time, if BM is causing problems at events then I would suggest that the kindest thing to do for your daughter is if your wife does not attend. No kid wants that kind of attention/distraction at their sporting events. That is how I would explain it to your wife. 

I don't know how reasonable or not BM is and if there is any way that she could be persuaded to be reasonable towards your wife for the sake of your daughter.??? Often with the women we talk about on here there is little reason that can be reached with them. 

As for your wife, I would maybe assess how much of your time you are spending at these events and what it is taking away from your relationship with your wife. If it is a large amount of time or clashes with important events then perhaps you could cut back on the number that you attend. Or perhaps you could show up for a brief period of time to show your face, but not stay for the whole event. 

Are there other things you could do with your daughter AND your wife so that you can start to build that relationship and show your daughter that you are a marital unit?

My only other quandry is why this offense deserves bringing up the threat of divorce? It doesn't seem like a divorce level problem to me. Is there other stuff going on that you could work on with your wife? Is being excluded from things a pattern in her previous life and those feelings are being triggered here? Are you also keeping your wife away from other people in your life, friends, family etc? Is your wife worried about you spending time in your ex's presence? Does she have reason not to trust you? - if you can work out what is going on then you will have a place to start from to find ways to make this situation work better for both of you. A therapist might help with this. 

In all honesty, I think you and your wife should divorce. Regardless of how the marriage began, it won't survive if there aren't any boundaries in place. 

I would be interested to hear more about BM. You've allowed her to cause a scene in public repeatedly. Why is that? That could be a bit part of the reason why you're daughter is uncomfortable about your wife.

I don't really understand people who believe that cheating ended a relationship. If cheating happened the relationship was already rocky, maybe even over, just existing as a legality. Should people be honest and end a relationship before starting another? Yes, but no person outside a relationship ends it, it's the two people in the relationship who end it, either directly or indirectly. There is a lot of talk about "breaking up families", but no mention of the families that are still "together", but broken anyway. My sister had a college roommate whose parents were still married, but refused to ever be in the same room with one another. By societal standards their family was still "together", but really they were more broken and likely more damaging to the children than a "broken" family. 

Your decision is whether you want your daughter calling the shots in your life or not. She shouldn't be dictating who you bring to an event and if your wife is sitting there minding her own business it shouldn't be an issue. 

Please come back and answer some of our questions, otherwise how can we help you?