As my mom tells it, when she woke him up and announced she was in labor and he needed to get snappy and get her to the hospital because I was on the way, my dad immediately hopped out of bed and combed his hair. Pantless.
Not much has changed in 39 years.
Re-enactment of my brother Sethie and Mary enroute to the hospital on the phone with my dad, soon to be Grandpa:
Mary: "We're headed to the hospital. Can you meet us there?"
Dad: "Should we just go to your house?"
Mary: "No, I'm in labor. My water broke. We're going to the hospital and I'm going to have the babies today."
Dad: "Oh. Well, we'll be there late tonight or maybe tomorrow."
Sethie: "DAD! We're having the babies right now. Where's Mom?"
Dad: "I have a doctor's appointment at 2:15. I can probably cancel it."
Sethie: "Good idea. Where's Mom?"
Dad: "So what happens now?"
Sethie: "I don't know, this is new to me."
Dad: "Yeah. It's new to me too."
Sethie: "Put Mom on the phone."