Can a man be in love w/ someone else, but not be w/ them b/c he stays w/ the mother of his kids?

Can a man be in love w/ someone else, but not be w/ them b/c he stays w/ the mother of his kids to give a home w/ both parents? Or does the man follow love and make 50/50 custody work w/ the mother of the kids and be with the woman he loves? Who does he truly love?