Someoneelse, you are definitely not immature or petty.  I agree with you 100%. 

I went through something similar when I was married.  My ex husband would talk about TV shows manchild liked and then try to get me to watch them with him, talking about his manchild the entire time.  It was weird, he would talk about things that would happen in the show that manchild really liked and get super excited about how his son like this particular part(s); it was like my husband was this child idolizing his hero and just rambling on and on about him.  Weird.  These were TV shows I may have otherwise enjoyed but that pretty much ruined it for me.  Not interested in the shows of the manchild and definitely didn't want to sit in front of the TV, snuggled up with manchild in the room and the two of them chit chatting like a couple of little girls. GAG.  That was a red flag that I should have picked up on - I remember thinking it was weird, like he was obsessed with the things his son liked.  If only I could have seen what the future would hold.....

I get that kids talk about their parents when they are young.. but at a certain point.. they need to learn to "read the room"... and at the point they get to be older.. into teen years they have to get that their parent doesn't want to have a running commentary in their presence about their EX! 

I guess I’m just a salty petty b@tch, because I would have watched the show with the volume up and made sure I was a few show ahead for spoilers. 

Spawn used to do a lot of stuff with Meth Mouth when she was married to second ex because he had money.  When she came to live with us she had to do what we could afford.  She expected the caviar lifestyle when all we could afford at the time was ramen.

Now Spawn is preggers with no job and the baby daddy has two kids so you know he pays mad CS, I see they take trips hiking, or to the lake nearby…because they are broke.  Yet his ex and her current husband post photos of them taking grand vacations with the kids.   For me it’s nice to see Spawn getting a good dose of reality and having to be the broke person trying to serve her “skids” (since she’s not married) ramen when they get caviar with their mom and step dad.

We are so traumatized from dealing with BM that any city BM has lived in and now her entire state is ruined for us. I think it is because we only have negative associations to those places. There was a country song I used to really like that SS said was BM's favorite. I can't listen to it anymore without a bad taste. 

If I find out BM likes something, I automatically don't like it anymore and if that's not a trauma response, I don't know what is. 

Ohh me too. It's annoying af. I would say to DH 'oh we need to watch x and y' and SD pipes up and I see her ready and think 'no no no' and she says 'OH mummy LOVES that show'. Ffs. Now I don't want to watch it. A song comes on that I love and SD says oh 'This is on mummy's playlist' and at one point DH even snapped and said 'SD we don't care'. Good bye song I once loved. It's annoying how toxic BMs taint everything.  This was one week where it was pretty constant and annoying. 
It's been a while since it's happened but I remember one time DH said we have to watch scrubs and I'm like umm yeah ok.. and asked if he's seen the whole thing and he's like yeah I have. I kind of in the back of my mind wondered if this was something he did with BM and one day I couldn't control myself and asked and he sighed and said yes and I was like ugh. Why make me sit and watch an entire series you have already seen with your ex? He also told me he loved the series bones and then BM was texting SD saying how she's laying in bed watching that show and it grinded my gears. Ignorance is bliss with this stuff and I hate to be told anything BM related she likes. 

That summer we planned a trip specifically to include SD16 power sulk. It was unfun, because Husband was a jerk. And SD16 didnt add anything positive.

Poland is ruined for me. Even all the wonderful food. I LOVE perogies, but I would rather stick them in my ears than listen to SD18 tell me over and over again about how BM is from Poland and eveything Polish is the best, and I know nothing because I'm from the east coast, not eatern Europe. 

No actual offense to any Polish posters here. It's just BM. 

We have the same. Sd tells me stories from her nuclear family home but i know she cant even remember that stuff cos she was 2 when her parents divorced. I know BM just feeds her this stuff. She also constantly talks about her mum or her mums relatives. Most of the stuff doesnt even have any content. But mostly the nuclear family stuff bugs me. Gor what ive learnt it was a total war back then. Ive told SO it bugs me. He rarely stats it but he just encourages her when she's at it and puts fuel in the fire.

Moving into our new (current) house. I didn't have any time to enjoy it because The Skunk Ape immediately kicked Little Idiot (SDnow22.5) out and she ended up right on our doorstep.

My DH and I have been dealing with this for 23 years.  BM mottos seem to be, "No good deed goes unpunished " and "whatever they do, I can do better". It doesn't matter what we do for or with the skids (big, small or seemingly insignificant), it had to be one-upped. One example of thousands that have occurred over the years, recently we went to visit one of the skids in the city where she is going to school, had a nice visit, lots of good chats, bought her some groceries, went out for dinner, etc.  Literally the day we left, BM flies to this city (unplanned, according to SD) and takes SD out for a one week long shop-a-palooza (hair, nails , pedicures, clothes, furniture, fancy restaurants, etc). Guess what we get to hear about. What we thought was a special visit, became very un-special by comparison. It continues to this day even though the skids are now in their late twenties to early thirties. It never ends.

No one can ruin something for you if you do not allow it.

Don't allow it.