No, there is no risk from this.
Hands do not transmit STDs, and STDs die quickly once outside the body. By the time you got to the bathroom, anything on your fingers had been exposed to air and whatever you touched (your drink, the door knob or handle, your zipper, etc.), and wouldn't have infected you.
STDs either need to enter your urethra - nothing did here - or require direct skin to skin mouth to genital/anal, or genital to genital/anal contact, which also didn't happen here.
STDs don't go through clothing, so her grinding on you is fine.
Really, you're fine.