You can get oral herpes via a grandmother's kiss. True, cold sores are not considered an STD, but they will show up in a herpes STD screen and the test itself cannot possibly determine where your outbreaks will be. Some STDs can be picked up by sharing towels, but that is pretty rare and via toilet seats is evern more rare. Crabs could be caught via sharing clothes or beddding. Molluscum can be picked up by simple, non-intimate touching, though they might not appear on the genitles if acquired non-sexually.

In short, it is difficult to acquire an STD without intimate contact. Difficult, but not impossible. I presume you are curious about something, so feel free to give some more details for a more detailed answer.