After receiving a hand job(only) at a private massage I noticed a white discharge the next morning and some irritation when peeing. We would be talking 10 hours after the massage took place. Is it possible this could be an STI or could the coconut oil she said she used have maybe caused this? Subsequently, thinking now this may be something she does for her other clients, could her bottle of oil be mixed with others cum and transfer me something more serious like HIV?  This seems absurd I know.. Thanks for your time!

You are correct in your assumption that 10 hours is too soon for onset of symptoms of an STD or any other infection. Generally 1-2 days is the absolute minimum, and most infections (common colds, most STDs, etc) require anywhere from 3 to 10 days, sometimes longer. Equally important, STDs are not transmitted by hand-genital contact. That includes HIV, as well as any infections that might be in whatever oil or other lubrication she might have used. That never has been known to happen.

Chemical irritation (e.g. from a spermicide, soap, perfume, etc) would cause even more rapid onset, typically immediate -- and also would predominantly cause pain and maybe redness, not discharge without pain, uncomfortable irritation, etc. So that's not it.

I would wonder whether your discharge occurred during or after a bowel movement. It's fairly common in some men for straining at stool, or stool compressing the prostate gland and seminal vesicles, to express secretions from those organs. Another possibility is residual semen from the ejaculation the night before, although that would be unlikely unless it was your first urination since the event. However, either of these usually would be painless, i.e. would not explain "irritation" with voiding.

So I have to wonder about an STD from a previous sexual exposure, e.g. if you had any other sexual exposures in the preceding 2-3 weeks. The safest thing is to see a physician, preferably one familiar with STDs, and certainly so if there have been any truly risky sexual exposures. OTOH, if the "irritation" was minimal and doesn't recur, and if there are no further discharge episodes, and especially if a BM or leftover semen seem to fit, you probably can sit tight.

I hope this has helped. Let me know if anything isn't clear. Best regards--  HHH, MD