i still dont understand this

every time i watch this movie, i dont understand why they move into HER apartment. did he not have his own apartment?? i would just believe he didnt have his own place, and lived with his dad and thats why they moved into her place. but through out the entire movie, he complains about every little thing about her apartment (which isnt funny, or endearing or anything) its rather annoying, so i thought ok why dont u guys go to your place then if you hate it so much? and if you dont have your own place, shut your mouth about how much you hate her place, because otherwise youd both be living with your dad, a-hole. every time i watch this movie, i try and like it, but i cant, because the only characters that are like-able are Renee and Hope and Hope's friend at the bar. Even Heather is more likeable than Mickey. She might be a cheater and this and that but she admits to being the way she is, Mickey tries to act like hes this great guy but honestly, id never date or marry someone like him in a million years.