Ok so this toilet seat is where his place he shares with a friend, or her plan she shares with a dude?
This aint some random toilet @ Whataburger!
Before I settled down I nail 2 chicks with vacant husbands. One actual came home while I was hitting it. Their little kid was I the living room playing when I heard "Hi daddy"! Trailer home bathroom window escape in that one. The other one was pretty clear that a man lived in the place.
They were at the place the chick lived with the dude.
Next time he takes a leak, he'll see the note the random guy left behind.
When he lifts the seat up.