hi i had a sexual encounter with someone where we dry humped with me with my pants on the other guy pants off i rubbed my penis against his ass i never came however what are the chances of getting an sti from this type of contact
Underwear is still clothing, so you are protected.
Chlamydia requires actual penetration to transmit - oral, vaginal or anal.
Oral chlamydia doesn't usually present with symptoms, and it sounds more like your partner has a cold, the actual flu or covid.
If you are concerned about STDs, you can easily be tested, as can your partner. Your partner should definitely see a doctor, though. He could have covid.
i just called the uk sexual health line in UK they mentioned that the risk is almost zero for what ive done and i shouldnt worry about it. even if my penis slipped out of pants(which im sure never) the risk would be highly low. i need to try and just keep it out of my mins