Hi Roseberry
I can empathise, I had a very similar problem only last week. I also have body image issues post-birth, and anxiety.
I hate the idea of strippers for so many reasons. I hate the idea of DP possibly being "excited" by another woman. I hate the thought of him being close to, and looking at another naked woman. I find the whole thing seedy and disgusting, "lad banter" at it's worst, as well as abhorrent from a feminist point of view.
DP is going away for a weekend on a friend's stag do. Somewhere fairly tacky (strip clubs galore I would imagine), but it does look fun from a "let's get drunk for hardly any money" perspective! It's not the stag I was anxious about, it was the likelihood of strippers.
I made my feelings clear to DP, how strongly I felt about it. It makes me feel quite sick! I'm happy to say that he took my feelings onboard and has promised to walk away if the situation arises. There are likely others from the group that would actually do the same, if someone else took the first step. This is coming from him, I did not ASK him to do this, and I do trust him to do it.
He also said that I wouldn't be mentioned, it wouldn't be a case of "the woman isn't happy with it rolls eyes, I'm so under the thumb...blah blah". He has taken the decision HIMSELF to not participate as he knows it upsets me, and will take the responsibility.
Have you spoken to him about how you feel? Does he realise how strongly you feel and how much it is upsetting you? I hope he has the confidence to walk away, despite the ridiculous "banter" and piss taking he would likely get.
As for the others, let them take the piss out of you. Just remember to remind them how pathetic and lecherous they are at every opportunity! Water off a duck's back.
Talk to your DP. Good luck. 