As one commenter, 'DovahQuinn', pointed out, the son's role in this photo gives a strange, dynastical perspective to the photo.
I like how the one son is just accepting his fate like: "This is gonna be me some day"
Sadly, we'll never know what the dad joke was, although we certainly know this man is a king among dads.
Here's a handful of suggestions as to what the dad joke could have been, adapted from some wonderful Reddit entries.
We hope you enjoy them.
I went to the doctor for a hand injury and asked him if I'd be able to play the piano when it healed. He said I'd be fine in a few days. I replied: "Brilliant, I've always wanted to play an instrument."
Rest in peace, boiling water. You shall be mist.
I recently joined a gym, but found it was a scam. Why should I pay for free weights?
The best pick-up advice I've ever been given is to bend your knees.
I'm friends with 25 letters of the alphabet. I don't know y.
I'd love to go to the local watch museum, but I can never find the time.