my bf is poly and i am not and he is in love with his best friend and he is deeply ashamed. it is destroying him mentally. what would you say is the best way to talk to him and tell him that i am not upset and that i want to help him be happy again? i know he doesn’t love me any less, i just don’t want to see him on the brink of self harm because he’s so ashamed of his feelings and who he is. i don’t know how to help.

If your boyfriend’s reaction to this is deep shame and self harm, he needs to see a mental health professional asap. That is not a normal or healthy response to feelings of guilt or frustration. I wrote about this in another post here.

It’s unclear from your message whether he’s pursuing this relationship or whether he’s staying monogamous for you. If he’s pursuing the relationship, and you’re okay with it, he needs to find a way to hear you and trust you and accept that this situation is okay. If he’s not pursuing it, he needs to let this go. Having feelings for someone else but not acting on them is a pretty common experience for people in monogamous relationships. He hasn’t done anything wrong by having these feelings. 

Let him know that you’re not upset, you know this doesn’t change the terms of your relationship, and that having feelings for other people while in a relationship is a normal thing. He hasn’t committed any cardinal sins of relationships or wronged you. If he can’t hear you when you say that, if he continues to be “mentally destroyed” and “on the brink of self harm,” he needs to see a mental health professional. You are not responsible for his feelings, and it sounds like there may be a bigger issue here that you can not and should not try to fix on your own.

I don’t know your boyfriend, or you, or anything besides what you sent me here, so I want to be cautious about accusing him of something I don’t have much evidence for, but I do want to say: threatening self harm and making a spectacle about guilt and shame like this can be a manipulation tactic. Saying “I have feelings for someone else AND I’M DESTROYED MENTALLY OVER IT” can be a way to make sure you don’t have any room or rights to get upset. If you two are committed to monogamy together, and he’s nursing a crush on someone else but making it your problem, that’s not okay. If this becomes something that drags you down or silences your own ability to ask him for things, think hard about whether this is a healthy relationship.