General question: How do you react when you're being asked for STD results?

Background story:
I had a booking with a new client, all good, we had good banter. A couple of weeks after he messages me asking about my STD results.
I should have ignored him. But I didn't.
I messaged the idiot that it's syphilis. He got worried. So I replied that at least it's not AIDS.
To my surprise, this joyless man didn't get the banter. So I told him that I was joking.
At this point, he started DEMANDING to know what diseases I was tested for. I blocked him.

I mean, honestly, it's his dick, his responsibility. He should be getting his privates to the clinic not messaging me?

I'd likely have done similar considering it was somebody I'd already met rather than some random texting out of the blue, but yeah, obviously a misfire and I'd be kicking myself for not spotting that he was in fact much thicker than I'd realised.

I'd just ignore for now - I suspect he'll be back if and when he figures out what a monumental bellend he's being. To answer the question in the title, I can't remember the last time I was asked, but I'd be pointing out that my medical history is none of their business and the only health they need to think about is their own.

I appreciate it can be annoying/insulting, but I feel it's best just to be honest and say roughly when you were lasted, and for what (assuming you got the all clear...), assuming you offer e.g. OWO.

I have never been asked about test results but one idiot had his one and only booking with me and as he was pulling his jeans back up he asked "I won't catch anything will I?"

 My reply was "hmmmm text me if your balls turn green in a few days time" I was glad to close the door on him and he knew it.
Any man paying sps should be fully aware of risks all round and I would bet my bottom dollar most don't get themselves checked at all.