Sorry, me again. I just reviewd from the beginn I ng. When I read the thread first time I must have missed the post where op said "I think what makes it worse is that I am not overly confident in my own figure, and hate the thought of him looking at all these slim girls and wanting that, maybe thats what is bothering me more?"
Op, I apologise for my rant. I completely misjudged your reasons.
Be confident in your own figure. You do not need to look the way the media says to be beautiful. You certainly are more beautiful and more desirable than you think. Your partner is with you because he wants to be with you.
How you look will change over the years for better or worse, who you are will make that not matter.
If your partner is a cause of your low judgement of yourself, then a frank assessment of the power dynamic in your relationship is called for and that goes way beyond what he does on a stag do.
My contested opinions are not relevant here.
Get assertive or get help to assert yourself. There are many commenters to this thread who'd be glad to help with that, I'd guess.
Not sure you're even still following this thread but if you are, sorry for any distress I may have caused you.
I still wish you luck and hope you and yr partner find a way to go forward in harmony but I'd like to add that it's more important to be in harmony with yourself.
Only my opinion. Yours is the important one