In essence then without the verbiage:
* You met a man at college some years ago
* You talk to him, but have not gone out with him it appears
* You see a picture on his social media which you find odd
* He removes it after telling you the name of the bar
Why do you care what he does? Why is it your business what he does to whom and with what? You're not seeing him, you're not g/f & b/f .... So?
Tripping? Yes I'd imagine you probably are; maybe once too often.