I think he has too much of a good thing; all these women who he thinks "need" him and make him feel good about himself. It does not sound like something I would want to be part of; he has no reason to change so you will have to decide if you like the environment he has created for himself or feel crowded out. It's not "wrong" but it doesn't sound like something I would want for myself? He'll never be exclusive to you, which is pretty much what a good relationship is about? Leave him for a woman who doesn't want a full-time man?

Pretend you marry him, buy a house and have 2.5 kids; he'll still be texting and spending emotional time with the other women, helping raise the non-son, etc. Would that be what you'd want? The non-son raising takes time, money, and emotional investment; do you want to contribute more so he can contribute that to someone else and their child?