i think at her age, she is still work for him. i know when i was going through the exact same thing, i felt the same way. how can you NOT love this little person (the way i do) and not want to spend all your time with her? but considering that i knew her every little quirk, what every grunt and giggle and facial expression is it was easier for me.
and even if you dont want to go out, you really need to take time out for yourself. i was the exact same way about not liking to go out and rather be at home with the family. you need to back away. even if you go to your bedroom and close the door for an hour. they need their time alone together.