Partner of a year is in a running group. He is now running on separate days with a 20 year old woman - as she lives closer to him and he doesn’t have to travel. He insists they are friends. I’ve told him I wasn’t happy but didn’t tell him what to do - I assume it was implicit. I thought, given how seriously I told him I wasn’t happy and it wasn’t appropriate, he wouldn’t run with her again. In actual fact, he is indeed planning another run with her. He said he invited the other group members but nobody wanted to join. We are in our 30s. He insists he loves me, doesn’t fancy her etc. To me, it just isn’t enough. I’m absolutely fine with his many other female friends.
AIBU to want to dump him over this?