Are you for real? if he spends on his wife its because he wants to not because he HAS to. And OP hasnt suggested that shes taking her husband for a ride and she has helped him out before. Its clear he choses to manage the house while she raises money to secure their future with a property. But seriously if he wants to loan money to his bhabis brothers wifes sister or whatever thats HIS responsibility. He should ask OP instead to help out in their household if its so much of an issue not take money from her so he can be generous dude who lavishes money at people.
Shes stated he spends alot but no one does the same on return so maybe he habituated to spending and showing his wealth.
Sorry if my husband asked me to lend 15k or watever amount for his family my answer would be no. Simply because i wouldnt expect him to bail a random relative of mine. Parents is different. He has a responsibility as she does towards hers. And clearly she has goals to secure her future not bailing out random relatives.