I would just be so proud that I banged someone so hot (In my eyes,anyway) That I would have to brag. I'd be flattered if my girlfriend bragged about me.
I'm a guy and despite the fact that I hang out with more girls than boys (guys tend tend to not like me because I think that porn is wrong and most of the guys in my school are disrespectful perverts that think that women are sex toys and nothing more) I've talked to and been around guys that accept me and I can gaurantee that any guy would do that. It's perfectly normal. However, I think the morallity of it depends on the way the guy talks about it. If a guy tells his friends that her vagina was sooooo warm and how big and smooth her breasts were, I think it's wrong. If a guy tells the story in a more passionate way like telling his friends that the entire time he couldn't stop staring into her eyes I think it's totally fine.
When I first joined HipForums, you'd a got way different answers. Now we're mostly pre adolescent in our ideas.
I do it, some of my friends don't - one even refuses to listen to me talk about it (I think he's into her though =P) Oh, and I wouldn't if my girl didn't want me to - but I wouldn't bother to ask beforehand - I was there, I should be able to share my side of the experience - but, y'know if she didn't want me to it's not that big of a deal, so why not respect that request?
I think it's poor form to "brag" or share intimate details about your sex life with anyone else, regardless of whether you are male or female. Talking to close friends about any problems, emotions etc., however, is perfectly healthy.
It seems like there's a double standard on this one, at least from my perspective. My friends and I were always taught that it was rude or inappropriate to talk about a girl's sexual activities. It was like "you've got a good thing going, but if you embarrass her, you'll lose it." Typically, you might make a side comment or give a knowing smile, but that was about it. It seems like this is universally accepted as the approach by most all the guys I know. By contrast, women seem a lot more open to discuss their sexual adventures with each other. As one girl put it, "we talk clothing worn, devices used, and positions"!!