Amost never. It is highly inappropriate and, in the United States, it is considered "sexual harrassment" if a man touches any part of a woman without her permission. Sexual harrassment is against the law, and a woman may bring charges against an offender.
It may be an indication of possessiveness or showing off, and is usually considered rather crude and inappropriate even with a romantic partner; although in some cultures it is a sign of affection and appreciation of a woman's "assets."
You can report it as sexual harassment.
Probably
This is a rude and inappropiate way of saying he likes your rear end.
if a guy grabs you by hand then it simply means that he is attracted to either physically or even sexually.it may not be necessary for him to like you
it means he likes you and wants u to be close to him
Usually when a guy hits yr butt he is either flirting with you or hitting yr butt because he thinks its really big an likes to watch it jiggle. Trust me i have had a lot of guys hit my butt an most of then were just doing it because they like it an like to watch it move. My boyfriend likes to always hit my butt because he thinks its big an like to watch it move an shake. So young ladies out there if a guy hits yr butt don't take it offensive unless its somebody that you don't know an they just walk up behind you an hit your butt. If that was to happen to me i would beat the crap out of the guy that done it to me. So ladies beat the crap out of any guy that hits yr butt if you don't know them. If its someone you know that does it just smile an sneak over to them an hit them right back on their butt.
A lot
Grin and bear it ... he's not your boyfriend yet, and obviously not the other girls' boyfriend either, he's just being a "guy" ... stop being so jealous, as right now he does not belong to anyone, including you.
It means he thinks you have a nice butt but doesn't like you.
They probably like them!<3
Not a real women
That depends.......what do you think when you look at your butt in the mirror?