(Maybe) Straight friend?

Okay there’s this guy I work with who’s the legitimately the nicest man I’ve ever met. I came out to him maybe a a year ago and nothing changed like I thought it would. He always ends our conversations by saying he loves me, he texts me all the time just to say hey, and asks to hang out all the time, he winks at me and blows kisses, and he even called me cute a few times. He has a girlfriend of 2 years, but he doesn’t really seem happy in the relationship. I love that he does these things to me and I DONT want them to stop. I just want to know if he’s just that comfortable with his sexuality that he doesn’t care, or if he actually has a thing for me. What would be an appropriate way to ask without things getting weird if he is completely straight? I’m afraid that if he senses that I like him then he’ll stop doing all the things I enjoy so much.