We've been together for 5.5 years, living together for the entire duration of our relationship. We opened our relationship 3 years ago - threesomes and foursomes, and he started developping feelings for a girl in September. It ended badly. He started dating again, with the intention to find someone he bonds with.

He's been dating Sarah (20F) for about a month. He told her in the beginning that he has a gf, she's his priority, told her about what happened in September and emphasized that he doesn't want this to happen again. He wants to make sure what happens between them does not bleed into his life.

Last week they had their first sleepover at her place, tonight their second.

They hang out from 2pm to 4pm the following day. He says he wants 1 sleep over / week 1 date night. It's a lot for me, but there's not much I can say, that's what he wants.

I ask him if he loves her, he says that basically he has no interest in dating other girls, he "chose" her, but that our definition of love (mine and his) are different so he's not sure how to answer that question.

I have peaked over his shoulder while he texts her and they are sending each other hearts.

When I ask him what doing this (seeing her that much) brings him, he said "you already know the answer" and I said "some fun?" He said yeah.

As you see, he is not very straight forward and I would like answers because I have been blindsided by his first romantic adventure (poly bombed, as feelings were not "allowed").

I'm not dating and not interested in dating.

What do you guys think? Is he in a relationship or just "having fun"?