I'm in a same sex monogamous relationship. About two weeks ago, I was running on a nearby trail. It was night and pretty cold. I met a guy and after some flirting we mutually masturbated. I've seen people cruise the area before. It's pretty obvious. There was no kissing or oral, just handjobs. There was no exchange of fluids that I can think of and not sure if he used spit.
The next day I had a light itch. The two days later started feeling what felt like a UTI or prostatitis. Frequent urination, slight burn, and a consistent pain in the prostate area. It's resided a bit but still ongoing. Today I woke up with a sore throat.
Last week I had sex with my partner and I'm worried I could have caught something on the trail. Is it possible to have an STI from mutual masterbation? Could it be side effect from stroking in the cold? Could it be a UTI? Or could it all be in my head and just anxiety wrecking my body?
I don't know about stroking in the cold - I'd doubt that. If it was cold enough to do harm, you probably wouldn't be out running in it.
STIs don't present with symptoms that quickly. It's a minimum of 2 days, usually longer. Maybe you got something in your urethra - were his hands dirty?
It could also be anxiety and guilt. We see a lot of that here. Guilt and anxiety are powerful and can manifest actual physical symptoms.
Make sure you drink plenty of water, and avoid alcohol and caffeine, and see if that helps. If you're a little dehydrated, you'll see improvement in a few days. If symptoms linger, see your doctor, but it's not an STI.
Remember that guilt doesn't equal risk.