Look, no parent is going to be able to stop a teenager having sex when the opportunity is in front of them. Not unless you want to stray into locked rooms, chastity belts and chaperone territory. Shaming your kid for it is entirely counter productive and will give him hang ups. I'm sorry but your husband has the right-ish idea. Going all out on the back slapping is way over the top but the excepting that your son is sexually active, ensuring that he has free access to birth control and making sure he knows that he can come to either of you with any issues? This is the way.

I don’t think he’s /entirely/ right assuming your assessment is to be believed, but thank goodness your husband was there. If you had been the only parent present the kid would have never trusted you with anything again and just would’ve carried on behind your back.

So, your plan was to deny and not help him with condoms? You're an idiot!

That's pretty normal for fathers and sons. I know it's a total double-standard, but at least he's giving the boy money for condoms, instead of financing more sexcapades.

With teenagers, you make sure they know about how girls get pregnant, you make sure they know about how you pick up STDs, you make sure they're doing it with someone their own age. You can also make sure they don't have to do it in dicey, semi-public places (round the back of the the bike shed it was in my day) by letting them hang out at your place. There's no point trying to stop them, they'll only go underground. You have to accept that your children are not pale copies of you, but individuals in their own right. Go read up Kahlil Gibran on children.