DH left at about 8.30 pm, which was about 3 hours after DS was born. He would have stayed if I asked him, but DS was having a big sleep and I was ready for a sleep, so it made sense for him to go home and rest himself so he could be back at the hospital first thing.

You're definitely not being unreasonable, and your DH probably wont even be thinking of poker if you have a new little baby by that time.