Affiliate Marketing Secrets

Very long story, summed up.
So a few years ago a friend of mine and his brother had some rough family life and ended up living with us. Lets call them K and J. At the time J was still a minor (a month away from being 18) so for a while he was in the social services thingy and they determined it best for him to live with us since his brother (K) was already with us, plus he could go to the same school and all. AFter he lived with us for about 10 or so days we went to an outing out of town that we were all a part of. J hadn’t been affiliated with the group because his mom was nuts (that’s part of the family issues of theirs). For no reason during the outing J accused my dad of molesting him. It def never happened-I was there. But there was a police investigation and no charges were ever filed. But it was a living hell for a long time. That was all 3 years ago.
Here’s my dillema. If I have a single enemy in the world it would be J, and I think I’m justified in feeling that way. A good friend of mine (call her S) is now dating J. Her and J were friends years ago in high school and he treated her like crap and they bounced between being friends and hating each other. She knows about how he lied about that stuff 3 years ago. My and S are good friends but we havent talked, texted, or anything since she told me she was dating him. I really think that I miss her in my life. But I kind of feel betrayed. It’s messing with me. what should I do? please help.