Hello! I separated from my AH in May. We have a 4year old son and a 10 month old. Me and AH told our son together about the separation. We presented it as a mutual decision (even though I had asked AH to leave). Alcoholism was not brought up as I don't think my son would understand and it would have just added more confusion to the situation for him. We both said we were okay with it and that things were going to be better this way. We didn't focus so much on the reasons for the separation as we did on what life was going to look like. We explained where daddy was going to go live, when he would see him, and confirmed that he(son) would stay with me. I'm sure with your children being older, they will ask their own questions. That can guide you with what to say. I'm sure my son and baby will ask questions as they mature.