kick him in the nuts again, this time ensure he reaĺly cannot have kids.

This almost sounds like he needs psychiatric help if he has that delusion so deeply rooted in his psyche that he apparently considers his "infertility" part of his identity. It also raises concerns in my opinion that he may have not only fathered other children, but have contracted and spread STIs/STDs because he was operating under the assumption he was firing blanks and thus sex without a condom or other birth control methods would be 'safe' sex. I would suggest getting tested if you haven't already, OP. Which isn't to say that he has to be cheating on OP- he could have had those prior unsafe relationships prior to marrying OP. That said though, there are multiple studies supporting the 'guilt transference' tactic cheaters use- in which they accuse the victim of being the unfaithful one, of being untrusting or paranoid, or of being the one in the wrong anytime they question the cheating spouse or partner's behavior. Them chronically 'spot checking" their partner, and otherwise trying to control who and where the loyal partner spends time are two more major red flags that the partner could be cheating. So if OP's husband is displaying more than one of these or severely displaying one, it might be a good idea to try to find out if he is cheating.

kick his ass then

I hope your son didn't inherit the dumbass gene

God what was that conversation like? Honey, I'm pregnant! You cheating *****!

Getting kicked in the nuts is a kind of a common occurrence in today's kids. I doubt it'll render them infertile.

Hes your husband and he doesnt believe you havent been faithful? Thats one of the reasons i personally would divorce. I wont stay with someone who 1 thinks i would cheat and 2 NEVER believes me even when i have proof.

Tell him to take responsibility or you will kick him in the nuts yourself.

My husband had actually wanted kids more than I did. We were together 5 years before marriage he had never mentioned this before and we didn't have unprotected sex until the night we were married. Our son is 4 and these accusations sprung up after he read some stupid mock article about how one blow to the jewels can completely ruin a guy. I actually considered him rather smart up until this point Lol. He tried to claim he was joking once all the test came back but I know he wasn't. He hasn't treated our son any different though thank God. Anyway sorry for the long reply anymore questions I'll try to answer them. TL;DR: Husband is an idiot tried to play it off like a joke didn't work.

OP, are you sure he wasn't kicked in the head repeatedly as a child? Refusing to believe the scientific evidence when it is shown to you is stupid. Refusing to believe the scientific evidence and preferring the lie of infidelity is morally repugnant. You are actually better off without him in your life.