"Anyone can end any social relationship at any moment. The other person just has to be alright with that."

Congratulations, Chloe. Yes, Billy is very Victorian, but somewhere between being so gay that he's hardly ever interacted with women or thought about them all that much and having a pretty messed up relationship dynamic himself, he's apparently not misogynistic enough to think that it'd be Chloe's fault if something happened to her in this case.

Di.. versity win..?? Y-Yay..?

"I certainly can't imagine having those sorts of interactions with anyone, but if you are enjoying yourself, Miss Frazer.. Then who am I to judge, hm?" Okay, he's still going to judge. But more just in the same way he's constantly judging everything. At all times. "Besides, we said we would have each other's backs."

Even if Chloe is making questionable decisions.