I'm an an LTR right now.
I suggest all men clear this shvt about exes before agreeing to exclusivity with a woman. As a condition to being my girlfriend, I went through her social media inboxes and all her
text messages, scouring them for ex flames. Any male in either, she had to explain who they are and what their history is. This was done in the heat of the moment so she couldn't plan for it.
The OP should have known about this guy before even agreeing to an LTR with her. She obviously has deep feelings for him. This relationship is going no where positive. It's best to cut her lose before things get ugly.