People keep hitting on my girlfriend

Relationships are great. No, really.  The comfort you get from having someone to share things with, to cuddle when it's cold, and to pluck your eyebrows when your monobrow is getting funky is invaluable. 

What's really great is when you go out together.  She takes hours to get ready, you spend hours drinking and waiting.  Waiting and drinking. She says those two words you have been wanting to hear for what feels like an eternity. "I'm ready". "Yes!",  you think. "No, actually I just need too...", she says. 

The false alarms pass and the time has come. And my God she looks good. I'm so lucky to have you, I say, and rush her out of the door before she can alter herself any more.

One cannot truly appreciate the obnoxious nature of any typical jack the lad until you have had one of them hit on your girlfriend.  I'm sitting with my girlfriend, drinking and chatting. No, wait, I'm holding hands with my girlfriend, drinking, chatting, laughing. Over waltzes some overconfident, smarmy, half dancing asswipe,  and loudly whispers in her ear ( I hate it when people do that) "fancy a drink, love?" 

I'm literally sat right here, man. She awkwardly glances over, to which I shrug my shoulders. Am I the gay best friend to this guy? Oh no, a guy who doesn't dance as he walks cannot be cool enough to be with a girl like this in any kind of romantic notion, he must be a gay best friend. He's actually probably into me. In fact, I won't even look at the guy, and I will continue to ignore her rejection, and keep hitting on her. 

The guy did not acknowledge my existence, and to be honest, I don't care. Five minutes later he was on the d-floor feeling some middle aged woman's inner thigh. Fair play mate, you had a go. The thing is, this happens an awful lot. Guys have tunnel vision when they see a pretty girl. Nothing else matters. 

I should take it as a compliment, right? Especially when some guy she works with comes up to me on a night out , and loudly whispers in my ear ( I fucking hate that) "if you weren't such a sound lad, mate, I would definitely fuck your girlfriend!" How on earth should I respond to that, as I look into his lecherous face, saliva dripping from the corners of his mouth?

All I'm saying is, guys, stop being so cock heavy all the time and think about what you're saying.  Not every female on the planet wants to have sex with you.