I just got out of shower and had another thought come to mind and that is "partner". The Doc feels more like a partner while my xw more felt like she was just along for the ride.
Additionally, it has been a little awkward for me to have my girls see me show affection to someone else other than their mom. Not for me but more for them, especially my youngest, as I see them watching.
Really since day 1 it has been all about comfort level. Honestly I probably met the Doc too soon.