He sounds like a perfectly normal insecure young man. The one's who shout loudest about girls are usually the least succesful. I get loads of grief at work from colleagues who do not understand the hobby at all, but let's be honest it is the same with most hobbies. I cannot understand the obsession some have with fishing. I just appreciate that they like it and leave it there. I would try and find out if this colleague has any other interests beside girls, whenever he laughs at you for your flight simming draw comparisons to his hobby, even if it doesn't work to keep him quiet it will make you feel better if you can get him back some times.
With the old "get a life" routine, are you happy with your life? If you are the best reply is "Already got one thanks, it's great fun." or something along those lines. If he really bugs you interupt him with something when he is talking to a pretty girl and start talking to her yourself, you have an interest which girls DO appreciate (Kimber, Stormy and Shorty to name just 3) and if he's into nothing but "girls" he'll lose out in the long run.
Will
Ps does this make any sense??
Will