I can say that the stranger behaved with the brunette on the bus as if they had known each other for a long time. He laid around flatteredly while the girl was sucking his dick, and they fucked each other without any shyness. The damsel took a ride not only on the bus, but also felt the powerful bumps in her hole from the guy's stick.
I take it this is one of the varieties of the ride around town. Guys offer bored ladies a ride around town in a car, and the ladies thank the guys for it this way. In this case, it turned into a threesome.