What do I do?

So I have been a clueless idiot and found out that a "straight" friend of mine has been flirting a lot in the last few months. He is touchy-feely, he has initiated intimate moments and being dumb I have reciprocated them. Eg: he complained about a sore back and really played it out, I offered a back massage as a way to help. I showed him a plant the scent, he said he couldn't smell it and so I grabbed his hands and made him rub the leaf between his palms. He also has a very effeminate touch and mannerisms when he thinks he is alone. He pushed me away today, but after a third person who was there left he came sat beside me, I decided to walk away and leave him alone. I could tell it bothered him. Should I ask him what he wants? Or just leave it and let the friendship die?