I don't shave down there, I have tried but it is uncomfrontable. I do however keep myself trimmed down there though. and that is not just before sex, I do it year round. Mainly because I like it that way
When I know I am going to be with a girl and there is a chance she will see me naked I make sure I'm trimmed up but I don't like shaving its too uncomfortable!! I will trim it really short though!!
Some do some don't. All guys are different. Some want to some don't want to. If hair bothers you you could ask your boyfriend to shave he may be up for it!