Just remember, he's probably still fertile, and will be for about 8 weeks.
At my vasectomy appointment, my doctor said, "you'll still have viable sperm for about 8 weeks, or about 12 ejaculations post-vasectomy."
I said, "12 ejaculations? Then I should be good to go by about this time tomorrow."
ba-dum crash.
He also said that until my follow up sperm count was completed, I should continue to use the same type of birth control I've been using in the past.
"By the way," he asked, "what form of birth control do you use?"
"My wife says that the most effective method of birth control for us is my personality."
ba-dum crash.
During the procedure, after he had injected my scrotum with a huge-azz needle to anesthetize it, he said, "even though I just injected some pain-killer, you may feel a tugging sensation on your scrotum."
"Thanks for telling me that, doctor. I'm used to that sensation, but not when anyone else is in the room."
be-dum crash.
As he was cauterizing the vas deferens, he said, "you might smell a little smoke from down here...we're using a hot tool to cauterize."
"No problem, doctor. I used to smell that back when I was a teenager all the time, until I discovered baby oil."

Yes, I really did say all of those. Yes, I was flying high on Valium. He said I was his most entertaining patient in 20 years of vasectomies.

Hairdog