Lowkey, you could tell them that. I don’t think it would be hurtful🤷♀️ only if you’re comfortable with that tho. My sister has BPD and sometimes, you do have to be up front with her in the same way she is with you or else she’s not gonna change/notice anything, if that makes sense. I say talk to them, and then distance yourself as needed. You don’t have to justify not having good friend chemistry with someone