If you've tuned in to The Tonight Show [1], you know that Jimmy Fallon [2] is prone to giggle fits, whether he's watching Taylor Swift [3] cry over a banana [4] or doing a ridiculous commercial with Jessica Biel [5]. But his easy laughter came long before his hosting gig — you can see it in action when he frequently broke character [6] as a cast member on Saturday Night Live [7] (yes, even more than Bill Hader as Stefon [8]). You can't always blame him though. It's probably hard to keep it together when Will Ferrell [9] does something utterly ridiculous, whether he's a posh department store manager in "Jeffrey's" or a horny guy in a hot tub in "The Love-ahs With Barbara and Dave." From conspicuous mouth twitching to hysterical laughter, here are all the times that Jimmy broke on SNL!