Should I take the risk and tell him how I feel?

I have had this crush on this guy for forever, but I don't know if he is straight/gay/bi. he was single for years got into a relationship that lasted for 3 months and now they are done. Were are in our late twenties, he was always making excuses like I have no time to see her and girlfriends are expensive. I workout in the gym he works at and I see him staring at me occasionally, sometimes he will place himself around me at the gym but doesn't talk to me unless I initiate. There is alot of other stuff to but not worth mentioning . Sent an anonymous email telling him how I felt but got nothing that confirms his sexuality. He said thanks but I'm in a relationship, and it was clear that I was a guy. I'm tired of beating around the bush and just want to ask him out. But he keeps on liking his ex girlfriends posts on Facebook and its making me not want to go through with it. Should I just ask him discreetly? And they broke up about 3 weeks ago.