Castells the PartyGlobetrotter

I've never really given much thought to how different men and women are except from the obvious parts, like we've got boobs and the guys have their little thingie, but the last few days I've spent a lot of time thinking about how weird guys can be sometimes. Don't get me wrong here, I love men, probably more than most women haha but right now I'm so confused. Please, please guys explain a few things to me:

♥ How can you even think of flirting with other girls if you are married?! I can understand an innocent flirt if you're in a relationship that maybe hasn't lasted that long but how can you walk around, talking about your "girlfriend" when she's actually your wife and even try to hook up with other girls?

♥ How can you sit close together with a girl at a fancy restaurant and tell her how special she is, thank her for always being there for you and tell her how much you need a girl like her. All this on the first date and then a few days after be cold as ice or at least totally egoistic and only talk about yourself, not caring at all about her?

♥ How can you start a sexual relation with a girl and not make the rules perfectly clear for both parties? Eventually someone IS gonna get more feelings and soon there will be problems. Why not just make things clear from the beginning and TALK about how you feel along the way?

Once again, boys please explain this to me, I'm dying to know! 
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