I think there are many Pakistani guys that not loyal to their partner....
Personally I know two of my friends were in this situation... they were dating at the time... and obviously broke off
It's easy for guys to go back to home land and find a new "masoom" rishta! and the girls remain broken hearted forevA!
You said many , it means some are loyal to their wives. I will say you are not generalizing , you are leaving room for exception, but it is other way around some are cheaters and most are loyal to their wives.
I am using the term wives as there is no concept of domestic partners in Islam and last time I checked most of the Pakistani are still Muslim. Also there is no concept of Western style dating in Islam. If one choses to do so specially with someone who is temporarily in some Western country for studies those girls are taking a big risk. As you said these boys can go back and find some masson larki.
Yes I will agree that most of the Pakistani men who are born and raised in Pakistan will have certain reservations against the girls raised in Western countries , specially if these girls are into dating they will think that these girls can never be loyal to them because since they are too frank and forward it will be easy for them to be friends with other men.
So it is better if these girls be careful and go for the traditional process of finding their husbands. Again I am not generalizing , not all boys/men from back home will have that kind of mindset but unfortunately most do.
During the dating period , the boys and girls are checking each other out to see if they can be compatible husband and wife or not so if a guy is checking the personality of two girls at the same he is trying to save time on his search for his future wife. If he finds out that one or the other or both of them are not his dream girls then he moves on. Cheating is taboo in Western countries during dating because the couples who are dating have sexual relations too, that results in an emotional bond and if one or the other cheats that is very hurtful.
I hope and pray that Pakistani couples who choose to date should avoid Western style dating so that this kind of emotional bond does not develop which can lead to hurting of one or the other.