Should I give him a chance?

There's this guy i've been talking to lately and hes recently told me he wants a relationship with me. I've developed feelings for him as well but im scared our relationship would fail. Hes a good bit older than me and when we first met I was only 16. He was 28. Our conversations back then were nowhere near romantic in anyways. I would basically just rant to him about teenager stuff, and he'd try to give me advice, almost like a mentor. He was also happily in a relationship at the time and they had two kids. The only time I really hungout with him while i was underaged was at his brothers apartment, right before i went away for college. His family is close to my best friend's family so we hungout with them over there for a night but we kinda lost contact for a few years. Until about 2 years ago. We were both recently single and we had both moved but ironically only 5 mins away from eachother. Unfortunately, his fiance had passed away and at the time he wasnt ready for a serious relationship, which i understood. We did have a casual sexual relationship for a little while but ultimately i decided i wanted more and tried to date someone that wanted the same. That relationship obviously didnt workout so im single yet again. and now hes ready for a relationship. But im worried about how our relationship started, if thay makes it weird. Also i know alot about his family and i already know the chance of them liking me is slim but i know hes extremely close to them. His step-dad also cheated on his mom with my bestfriend which makes things even more complicated. But is all that a good reason to not give him a chance?