My SO and I plan to marry next year (we should be engaged in a month or two). I've mentioned it once or twice in passing, but once we are engaged I want to start working on a pre-nup. I feel very strongly that this will protect us both. His last divorce from BM2 was long and drawn out and messy as she was so greedy and wanted all of his money. She even raided her step daughters college fund (who she loves sooooo much bla bla bla). Disgusting woman. I obviously want to go into my marriage in love and trust and good faith. I love him very much. If we ever, god forbid, get to a point where we divorce, I don't want to turn into us hating each other and fighting over money. I'd rather lay things out in advance so we can have peace.

Background is that SO is 20 years older than me. He makes high 6 figures and I just hit 6 figures, so we are financially well off. People assume that he is my sugar daddy due to our age gap, but I am completely financially independent. I have a large 401k and Roth IRA in addition to my own savings. I have never taken a single dollar from him and we take turns paying for most dates. He wouldn't have been able to keep the house post divorce (when he was paying her off) if I didn't move in and help with the bills. I have no children and he has 4 (2 with BM1 and 2 with BM1)

I will also be having my lawyer prepare wills, living wills, health power of attorney,etc. He is the beneficiary on my life insurance and 401K and Roth IRA, and I am the beneficiary on his.

Do you have any advice as to what should be included in the pre-nup? Any step-related things that you wouldn't necessarily include in a "regular" pre-nup?

Some things I was thinking:
1) Any debts incurred before the marriage, including future payments such as child support and court ordered college funding, is the responsibility of the party whose debt it is. I want to make sure he doesn't come after me for money towards his future child support or college funding for HIS kids. I don't think he ever would, but god forbid he lost his job and I was still earning, I don't want to take on that debt

2) If we divorce, if SO decides to keep the house he must pay me back what I have put into it. If he sells it I receive my portion back. SO owns the house and it is in his name, but I pay about $1300 towards mortgage, bills etc. each month.

3)I would like to put in some sort of infidelity clause....like if our marriage dissolves due to infidelity then the offending party owes the other X%. I know I will be faithful and I know SO will, but he has wavered in a past relationship

4) His last wife cleaned out his retirement savings, which is disgusting considering they were only married for less than 3 years. I want to make a clause like your SO is entitled to Y% of your retirement for each year they are married. This would apply to me as well, of course. In addition to working an important job of my own, I support SO so he can be a high level exec. There are plenty of times I pick up his kids, dry cleaning, switch out cars etc etc so he can continue working and earning. He wouldn't be where he was without me, his supporting partner. Do you think this sounds fair or greedy? Obviously he would be entitled to Y% of my earnings as well

5)Should I put in some clause about if we have a child together?

I literally have no idea what I'm doing. Who out there has a pre-nup, and what does it say?