The act of insertion without thrusting, as a loophole to pre-marital sex. Sometimes with the added mechanism of having a third party jump up and down on the bed to approximate thrusting without the actual partners doing so. The idea being that it's not sex so long as neither person is actively moving to produce any pleasure.

Kind of like trying to use oral and anal as a loophole.

I'm not sure if soaking is something that actually happens, or more like rumors about kids eating tide pods or "rainbow parties".