Why do cheaters get married?

Recently my Mom told me that my uncle proposed to his long term gf and they’re getting married. My first action was to roll my eyes. He a CHEATER and last I heard, she left him after he physically abused her (according to her). She calls making a lot of allegations of but stays with him so idk what’s happening as I’ve never witnessed anything. When I see them, they act in love. The only thing I know for sure is that he’s a CHEATER.

Anyway he went and bought a ring and proposed and everything. Every time I see him, if his gf isn’t there, he’s hooking up with some chick I’ve never seen and it’s never the same chick. I don’t think he’ll ever stop cheating so WHYYYY propose to this woman? It’s just hard to get excited about a wedding under these circumstances. I’m definitely not excited about going or anything and I hope I’m not invited. I don’t wanna waste money attending a wedding when I know the groom with be put his dick in anything breathing.

Vent over. Thank you