Even the highest risk exposures, such as HIV infected semen deposited inside a partner's vagina or rectum, the chance of transmission for a single exposure is once for every few hundred to 1000 events. That's why many spouses of HIV infected people often go several years without getting infected (which maybe you didn't know).
Mucous membranes or not, the events you describe are zero risk. Stop searching the web about it and move on without worry.
Yea you did. Sorry. Im just paranoid because these health websites say that you can catch HIV if it gets in contact with a mucous membrane(eyes,mouth, and nose) so that's why Im freaking out.
Thank you for responding. Im a little concerned that I touched his underwear with my nose after smelling. Is the likelihood still non existent?
Welcome to the forum.
Responding to the title of your question, before reading anything else: If sniffing semen was your only potential exposure to HIV, you are not at risk, do not need testing, and should not be worried. HIV doesn't travel through the air.
Now I have read the question itself. My reply is unchanged. (I'm interested that you have "read all the forums about smelling semen". I don't remember ever seeing a question about it -- yours is the first!) There is also no risk if semen came in contact with your nose. Even unprotected sex would have been risk free, if your friend's history is correct that he has HIV with an undectable viral load.
Best wishes-- HHH, MD