I have been married 16yrs, 2 yrs ago i met this guy who is 9 yrs younger than me. we had an affair for a year?

we had an affair for a year and a half, and he kept wanting me to leave my husband, however my husband is an alcoholic and i feel responsible for him. in may, me and my friend had a bad breakup and he went back to his ex ~ who has been married and divorced twice and has two kids ~ i txt him after month a and he said they were getting married in november, then we talked the whole hour of his lunch break. the next day we talked again and he wanted me to send naked pics which i didnt. and he also said he liked seeing me naked.then i texted him monday to tell him i got a job, and that me and my husband were on trial separation, and then he said he couldnt text me cause of the gf. the gf were his workds he did not say my gf, which i find weird.he is not a jerk, he is a nice guy and he waited on me for a long time, why would he talk to me 2 days then say he couldnt? i want to remain friends with him because he was my best friend and helped me through a lot. i miss him a lot and would like to be able to keep contact with him.