Please don’t judge me but give advice.

So my husband and I decided to bring another female into our marriage. Basically like a girlfriend for both of us. She knew abou us being married, knew if she slept with somebody else all bets were off, and some other rules we had applied. Anyways we had a threesome and it was all good till she told us she was exposed to an std by another guy. We both were tested and were clean (thank god). We cut anything we had based off the fact that we can’t trust her.
Well Hubby still talks to her from time to time as just friends. He’s never lied or cheated to me so yes I trust him. I just don’t like the fact they still talk and see each other. She still will make an attempt to kiss on him but he will push her away. I’ve seen messages with her getting upset cuz he wouldn’t come over to have sex with her. Plus I’ve heard convos. Would it be wrong to contact her and tell her to go find somebody else cuz she isn’t getting my husband again? I really want to tell her to go find another man and hope he doesn’t hide her an std too. That’s just me being petty.
Please don’t be negative, take that shit else where. I just want advice
Achieve your health goals from period to parenting.