no you don't have to explain anything to either one of the families. not your side and not his. it is your decision. it not only affects you but your children. i personally believe that it is worse for the children to stay in an unhappy relationship because children are very perseptive and they can pick up the negative vibes in the home. so what if you can't provide the luxuries that their father can afford. what you are responsible for providing them with is unconditional love and understanding. material things do not make up for their emotional needs. you need and deserve to be happy as well. hope everything works out for you. please don't vanish, just try to sort things out the best way you can and whatever is feasible for you to do at this time.