My partner has recently developed a new crush on one of his friends that I’ve always been suspicious of them being a little more than friends. He’s recently told me they’ve been fucking around and stuff and it makes me feel very overwhelmed and uncomfortable. He’s told me for so long he didn’t like her and nothing would EVER happen with her and now they’re fucking around and that hurts. I don’t feel comfortable around her anymore and I don’t know what to do. Idk if I can handle this?
I have genuinely no idea what you mean by “fucking around” and I am not clear from your letter whether you and your partner have any kind of open/non-monogamous relationship, so I am afraid I don’t have quite enough context to give great advice.
What I can say, though, is that if your partner is doing things that make you feel uncomfortable, talk to him about it. If he is dismissive of your discomfort, or has any stance besides total willingness to resolve this in a healthy way, then leave the relationship. If you are already done with him about the lying and the hiding, leave the relationship. You deserve to be with someone who isn’t going to minimize your concerns, deny that they’re doing something they’re actually doing, and put you in situations that make you feel uncomfortable and overwhelmed.