I need advice!!

So at one point I was in a terrible relationship and I had another guy that would talk me through it and make me feel good.. when I eventually broke up with the manipulative asshole I was with, I wanted a relationship with the other guy.. I was in love with him.. he never wanted to go further and blamed it on his anxiety..

I eventually met my now fiancée and father of my 3 month old son. I love my fiancée with everything I have.

The old guy that I loved, I completely cut off. And I purposefully ended our friendship terribly so he wouldn’t want to continue talking to me, because I did cheat on my scumbag ex with him(do not judge me for that. My ex gave me heroin without my knowledge, he was a PIECE OF SHIT and I have no remorse for cheating on him.)

With that being said, on February 13, he (the guy I cheated on my ex with) tagged me in the photos he has of me on his Instagram, and wrote ‘I’m in love with this girl’. It’s been two years since we’ve spoken.

I can’t stop thinking about it. I guess I have a feeling of missing out? We never had a real relationship.

So my advice that I need is, what do I do? I know he did that to get my attention, and knowing I cheated in the past I think he believes I would do it again. I WOULDNT. I just want HIM out of my head. How do I get closure? Please help me.