Why do guys act different after you date them for a long time?

OMG feelings surely have changed over time, and so has the love for him. Seems it did diminish over time.

But I could say something from my view point, for a guy the first few months are very exciting. Flirting, those not so casual touches when no body is looking, romantic chit-chat. With time this effect starts waning out.

This only happens when from the start the love was not that your conscience would have made you believe, but something that impulse drove. You look too young hope it was understood pre-marriage.

He was always a rude, disgusting pig. You just didn't notice in the early relationship. He probably thinks you were nicer too.

Thats easy. SOME and only SOME guys think that when they get the girl after a while they're done and only have a ring to get then.

Imo, I think the more you're with someone, the more you grow with them and see all their characteristics and how they are when they don't have their guard up or anything really. So they take it for granted that you'd accept them for who they are. I don't think they mean to be rude or anything, but if it's really bad, and I was somebody who dated someone like that, I'd set things straight. Then he/she wouldn't be rude much.