During the 'Celebrity Family Feud' skit of 'SNL' last night (Dec. 21), which featured CBS network stars versus NBC network faves, Jimmy Fallon played Jim Parsons from 'Big Bang Theory.' Musical guest Justin Timberlake, in turn, played Fallon to manic perfection.

Since Fallon and Timberlake exhibit brilliant comedic chemistry together, be it on 'SNL' or on Fallon's late night talk show, watching them flip the script was brilliant.

Timberlake expertly aped Fallon's super posi mannerisms and personality, so much so that Fallon himself burst into giggles mid-skit. He's known for doing that ... often!

Timberlake struggled to keep a straight face but he managed, even when survey said that the No. 1 thing that men need to do in order to be sexy is...be Justin Timberlake. Natch!

It was a very meta episode!