My ex (5 years ago) has been trying to get me back?

My ex boyfriend we were high school sweethearts we dated for 5 years and then broke up because our life's were going in different directions, he's been married for 2 years now. I been with my current boyfriend for 3 years and he's been telling me he wants to divorce his wife and be with me and he never felt the same with her as he did with me? I told him I'm in love with my current boyfriend and he told me that it won't ever be the because we were our first loves. I met up with him just because I havnt seen him in forever and he hasn't changed he's funny and sweet. But he's still married? I know I should've even met up I told my current boyfriend I was going to meet up with a old friend so he didn't mind. I don't know what to do?