Sex online bookstore
This will result in one of two things happening -- the other person will either oblige or refuse.
If you are not ready to be played with, stick your finger back through the hole after he does. There have been many occasions that I have refused to take turns and just wanted to make the guy cum.
Most (not all) adult bookstores have an area where you can put a token, a dollar bill or a quarter into a slot and have an adult video play for about 60 seconds on a TV screen in front of you.