What are some signs that an older man is into you? Does it seem like he likes me or is just being nice, and why? Thx!?

Im friends with one if his colleagues, &was going to dinner to catch up w her, &then at the last minute as we were walking to the restaurant, I see him walking up to us, &she turns to me& says, "I hope you don't mind I invited [guy] because he REALLY likes you," &she turned around to look at my face as she said it. Another one of his friends who I was friends with before I knew they knew each other told me "you should go find [guy] while you're over there," because we were going to be in the same country briefly over the summer

There have been signs like him asking me about myself& really listening, &hugging but he hasnt made any really obvious moves, so I just want to know what an obvious move would look like from a guy this much older than me...does it seem like he likes me? Once, we were at dinner in a large group, &the group was all sharing their dating experiences, but someone made a joke that changed the subject &so I never got to talk about my own dating habits, but when everyone was leaving the dinner party, I saw him lean over& whisper something to his same female colleague who I'm friends with. I thought they were saying something about me at first, bc he was looking at me while whispering,but then I thought its just a coincidence - sometimes ppl just have to put their eyes somewhere while they talk, so I dismissed it, but as I was leaving, this colleague held me back& said "Ive never asked you, but are you seeing anyone?"