Suggest Treatment For Red Pimples On The Buttocks After Unprotected Intercourse

Question: Last night I went to a man's house. While we did not have sex (oral, anal, vaginal), there was hand to genital contact (my hand on his genitals). This person has recently (and regularly) engaged in unprotected insertive oral and anal sex, but not with me. The first thing I noticed was a small pink mark (he was an XXXXXXX XXXXXXX Male) just below the head of his penis that looked like a skin tag. I attempted to avoid even hand contact with it since the skin on my hands are dry. He said it had always been there. However, I also know that there was some pre-ejaculatory fluid on his stomach. While I did not touch it, he did. He sort of rubbed around. I am fairly certain it was dry by the time he proceeded to squeeze my right glute (butt cheek) with the same hand (maybe a minute or two later). He squeezed it a few times. It did not go near my anus at all, however it may have come into contact with some raw skin (or skin that felt raw when I showered earlier in the day from wiping after defecating). There are also a small amount of tiny red pimples on my butt cheek as well. Again, there was absolutely no penetration whatsoever. I am trying to see if I am at risk for HIV or any other STD based on this encounter. Attached is a picture of my glutes for your observation. To my knowledge there were no lesions, cuts, scrapes, or areas of broken skin that this most likely already dry (and very likely a miniscule amount) of pre-ejeculate came into contact. I believe it was simply on one or two fingers. So, did this put me at risk for HIV or any other STDs? I also came home and showered after.

Thank you! What about Syphilis, Gonorrhea, or Chlamydia?