Yeah, I just did a look-search and came up empty on that one.
It reminded me (slightly) of another school bus driver story that I had read years ago: told from the driver POV, he gets a flat with only four teen girls (girls from a catholic parochial school, mind you) left on the bus, out in rural woodlands. He gives them permission to get off the bus while he changes the tire--which takes a while. When he finishes, he sits on the first step of the bus and wipes his brows and wonders where the girls went. One comes back at that point and tells him they are all down at the river (a short walk away). He follows her and his eyes bulge out as he sees them all skinny dipping. He accepts their invitation to join him (it is quite warm) and soon they're flirting and the older one basically invites him to screw her.
Does that ring any bells with anyone?