Just when you think you'd seen it all.
An eagle-eyed footy lover has spotted the rather unusual way two Roosters players celebrated during their second round clash with the Bulldogs on Friday, catching the split-second moment on film.
David Grant uploaded the clip to Twitter, wondering if anyone else had seen Latrell Mitchell and Ryan Matterson's "celebratory handshake/ cock touch".
That'd be a no, then.
Grant was soon inundated with comments on the video, which is clocking up thousands of views as NRL viewers flock to check if the sack tap is for real.
Since Mitchell and Matterson were celebrating a tackle rather than a try, we're going to assuming it's some kind of "tackle" reference - but, either way, we'll be keeping our eyes peeled during their game against the Knights this Sunday evening.
Listen Live: Take a look at the games we're calling this weekend on Triple M.