I knew Ayl was down for it, but Versa sure surprised me. Without any fuss, this girl was getting ready to offer herself to Naoki as her way of saying thanks for all his help. I don't even think Versa was in love with him either, only Sera was (madly) in love with Naoki.
MC is told he can pay for brothel services:
"For the brothels, it's more than worth it!"
MC is offered free (not romantically motivated) sex by attractive girls as gratitude (Versa) and for fun (Ayl):
"No, no I definitely can't! That would be too much!"
Does he have a kink for paying strangers for sex? I'd understand if Naoki considers Ayl and Versa like family, which is how the MC from Death March gets away with going to brothels for sex despite having a party full of cute girls. But he's never said anything about seeing them like family; they're just friendly travelers he has (temporarily) accepted in his party.