v, The act of bag tagging your boyfriend/spouse's balls in front of his father figure. This is usually followed by a lot of weird explanations and red faces.
Erin fishbacked Rob right in front of his catholic father. The poor bastard.
" I almost made it up my driveway when suddenly I fishbacked right in the car"
Jesse: "it's gonna suck getting old, you can't help fishbacking all the time" Jeremy: " ya I know, I just started fishbacking after staying at payne's"
" I can't wait to get home and Fishback this cannoli"