I'm interested in advice on what you would do in this situation.
Have a close friend, let's call him Dave. He's one of my best friends, we speak most days about a range of things, and are very open with each other and see each other often. When I was single I told him I'd developed feelings but nothing happened - I didn't know at the time he'd started seeing someone else (was a couple of dates in), and tbh don't know if he ever saw me as relationship potential anyway. I asked for a bit of space to work through my feelings (he said take the time you need and the door is always open), which I did, ended up getting back together with a significant ex, and got back in touch with Dave to say the feelings were gone, and we became friends again. DP knows the history and is fine. I also enjoy the friendship much more than I did before as well given the boundaries are clear for me.
A few weeks ago his other relationship ended (he was really sad about it), and I have been hearing from him much more often - almost more than I did back when I was single, and he has initiated more one on one time. We went out drinking last night in a group though and, for the first time in our entire friendship, he was more physically demonstrative than usual - nothing seedy, but patting me on the head, lightly touching my arm sort of thing, going in for hugs, and spontaneously kissing me on the check which has never happened before. We'd always maintained a really strong no-touch barrier before, so it was out of character. But, later on, he left me completely alone while he went off to hit on a girl in a bar, which has also never happened before.
Would you ask what's going on? It's confusing. I want to stay close friends etc but it's been playing on my mind.