Is he interested in me/trying to date me or just veing nice? He's 40 and I'm 26 - I like him but I cant tell - help!!?

I'm friends with one if his colleagues, and was going out to dinner to catch up with her, and then at the last minute as we were walking over to the restaurant, I see him walking up to us, and she turns to me and says, "I hope you don't mind I invited [guy] because he REALLY likes you," and 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 and really listening, 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, and the group was all sharing their dating experiences, but soneone made a joke that changed the subject and so I never got to talk about my own dating habits, but when everyone was leaving the dinner party, I saw him lean over and whisper something to his same female colleague who I'm friends with. 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, so I dismissed it, but as I was leaving, this colleague held me back and said "I've never asked you but are you seeing anyone?"