If he is giving them money now, he will continue after marriage. If his family is leeching off of him now, they will after marriage. If not, now is the time to discuss the problem. There are too many men who refuse to leave their father and mother. There are too many women who refuse to leave their parents.
Extended families are famous for breaking up marriages.
NOW is the time to get the problems straight. Please do not marry a man if there is even a shadow of a doubt that you are totally attracted to him physically. Too many women lose their husbands because after marriage they stop having sex. The reason many women stop having sex is because their husbands are cold, rude, abusive. Women who don't want sex with their husbands are women who married the wrong man.