Because the egg cracked a yolk.
An egg gets laid
He cracked up.
They both like to crack open a cold one
The ice might crack up! I use this at the beginning of conversations... it's a reall ice breaker.
Because part tickles.
So accountants could have someone to laugh at.
Because he felt like BACON!
The same way British people pronounce beer can.
Tell it a yolk.
It's just a Yolk!!
