wow. my best advice would be to remove yourself from the case asap and really contemplate whether your relationship with the dad is in your (and the child's) best interest. both of you know you were in the wrong from the beginning otherwise this relationship wouldn't be hidden. i can guarantee that once the mom finds out, she will go for blood and will gain custody of her child and you will lose your license. i see nothing good coming from this whole situation.
working private duty, we have to remember that someone's home is our work place, an imaginary hospital, so to speak. we have to draw the line between personal and professional and stick to that.