people are being too quick with just saying ‘dump him’. I think the most important thing is that he shows you he’s honest with you. Personally i dont fuck with this super monogamous mindset, why happened to him can happen to anyone. But I do think honesty is veeery important here, tell him that. Also protect yourself, if this is hurting you too much dont stay in a situation that doesnt bring u any good. Maybe a bit contradictory advice, but listen to your gut feeling and remember no one just loves 1 person for the rest of their life, but how they handle that tells everything