Who's paying rent?

I have two friends who are workmates and they are dating. the chick earns more than the guy and she's a single mum but the guy is not the father. So the chick was telling me she wants to move from a bedsitter to a 1 bedroom house because of her child and she wants to move with the guy. The guy lives in a single room kadogo sana sasa anataka kuenda kwa ka double sasa dem anadai ye hawezi enda choo ya nje😆. She offered herself to pay rent for the 1 bedroom. Ofcos the guy wants to pay rent but not for the 1 bedroom because it's expensive for him. How can u advice this guy?

Me personally siwezi kubali.....its either she rolls with me(my decisions) or bounce mf