It seems this man is under the unfortunate delusion that he’s actually in a relationship with this girl. If I had to guess, she’s “dating” this guy for the free food and whatever else he pays for. I’m sure we can also assume that the guys she goes off to meet alone are the type of guys she actually finds attractive, and likely aren’t simps. If she says she’ll stay loyal, she’s already getting it from a bunch of other guys and is lying to you.