I'm still pre-op but, as a single woman, I worry about this too. I don't want to be more self-conscious at my goal weight than I am now. I've never been too weird about being naked around a guy I'm "involved" with. My train of thought was always "he can tell I'm a big girl. He obviously knows what he's getting himself into." lol However, the reasons for the body consciousness are obvious now, whereas after surgery they may be hidden. Yes, I worry too much... I've focused way too much on the possible negative results. Ugh!
BUT, I will say that making your insecurities known just make them that more noticeable and apparent to men. Do whatever you can to make sure you feel confident about some of the other parts you can control... in an event like this I always make sure I have my toes, nails, hair, make-up done, everything shaved that needs to be, undergarments and outfit planned! It's all about getting into the right mindset!
To echo some of the others, "if at first you don't succeed, try, try again!"