Hey,
I will try to help. But of course we can only play the odds. Receptive Anal sex is just about the riskiest act you can partake in.
That been said I hope this is reassuring.
First of all this is a friend, it’s probably safer to believe a friend is not HIV +ve if he says he’s not.
HIV is not all that common anymore in developed countries. Especially undiagnosed untreated.
I estimate we can be 98-99% sure that your partner didn’t have HIV - of course unless you know anything that would increase that risk.
Next receptive anal sex without ejaculation is estimated to be 1 in 170 (and I’d say the brief nature of your contact COULD even be lower)
So even if he has HIV and was infectious (not on meds) then it’s not a guarantee that he passed it to you.
So if we times 2 in 100 chance he had HIV with a 1 in 170 he passed it (again estimates) that’s 1 in 8500 chance.
High enough that if you would have asked for PEP then it probably would have been an idea. But it’s too late for that now.
It is low enough however not to panic. So please don’t.
Modern lad based 4th gen tests are said to be conclusive at 6 week. They used to say 4 week but they now say it’s 95-98% accurate at 4 week. That said I personally would take one at 4 week. As if negative would lower your odds to 1 in 170,000 (zero for all practical purposes)
You could of course ask your friend if he didn’t mind taking a test. There is rapid at home test kits that are very accurate. The blood ones. If he’s negative as he claims then you know you are in the clear. If he’s truly a friend he would do this.
Good luck hope this helps
A one time anal sex exposure is less than 1 percent chance of transmission. And it is a close friend so not an unknown here. Most doctors will NOT prescribe PEP for a one time exposure with this as it is reserved for situations in which there was unprotected sex with someone confirmed HIV+. This is a friend and a one time occurrence so the chances while not zero are so low it would not warrant pep. Since it was a risk, I'd take a 4th generation DUO test which gives a reliable result at 28 days and beyond and I'd expect it to be negative.