Run a Train

To "run a train" is to form a line of people that will consecutively have sex with a single person. This can come in the form of a Gangbang where a line of people forms to have sex with a single person. Mostly referring to a female or feminine person being the recipient of multiple male or masculine people, this is also used in the gay scene sometimes.

This term is used to refer to both consensual and non-consensual encounters.