Married man

im 21 and just got a new job in the past couple months. thats where i met him. hes in his mid thirties and married. has kids. i truly thought he was seperated from his wife the first time we hooked up. the next time we hung out i figured out he was married and i was very upset at how easily he hooked up with me as a married man. although that didnt stop me form doing it again. its been a month or so now and we are still seeing eachother occasionally. the time i saw him before last he said he couldnt see me anymore because he dosent want to sneak around and feels like its unfair to me. then i saw him at work the next day and next thing you know were hanging out again. we've talked about the situation and he says he dosent want to leave because of the time he will loose with his child. he tells me things are not good with his wife. they have only been married a couple years. i still dont know him that well but we get closer every moment we spend together. and i crave more of him. to have him in a way i currently cant. i just dont want to believe its not going anywhere. im suprised at what we are doing and i never thought id be seeing a married man. he insists his intentions were never to be physically involved with me. he tried to do the right thing by not seeing me anymore but its hard to stay away from eachother when we work together closely. im scared for whats to come because i really enjoy his company and think we would be developing into something real if the situation was different. how do i do the right thing? when being with him feels right but is so wrong. i dont want to complicate his life or mine. i just wish i had the chance to get to know him without it being a secret.