Is he interested in me and trying to date me or just being a nice guy? He's 40 and I'm 26 - I like him but I cant tell - what are the signs?

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?"