Third-Party Intermediary (or Intermediaries)
TPI stands for a lot of different things. I'm just giving one of the definitions here, which is used in certain military/ government/ police situations, also in the worlds of business/ finance.
The setting for my example is a hostage situation (if you've watched the first episode of "Flashpoint" you'll recognize this).... One lone hostage taker has a gun to the head of his hostage. Police presence is all around. A civilian who clearly knows the hostage taker is seeking to intervene.
Police 1 to Police 2: "Hold fire, we have a possible TPI here."
The act of running, hopping, and/or jumping one's way across the stretches of human dumped rubble or natural rock found along normally along shores or coastlines, although can be found elsewhere. Practiced to improve agility, quick-thinking, and path-choosing; a kind of intermediary stage between cross country and free running .
"Jared was rubble-hugging at Los Lobos Point yesterday, man was flying over those rocks!"
A person who acts as an intermediary in group sex. allowing a person to to be in a sexual act with another person without being in physical contact with them.
"I slept with Karen last night!"
"Dude, isn't she a lesbian?"
"I used Jessica as a fuck-buffer."
"I heard you were at Mike's orgy last night. Doesn't he have the clap?"
"Yeah, but I used Lillith as a fuck-buffer so it's all good"