How I Met Your Mother: 10 Worst Things Lily Ever Did

10. When She Brutally Beat Up Marshall's Colleague Jenkins

A new employee named Jenkins is hired at Marshall’s workplace. Marshall is particularly fond of Jenkins because of the wild and funny things they do, in and out of work. Ted picture his new work colleague as a goofy, fat man and is surprised to hear that Barney wants to sleep with Jenkins. The truth is revealed when his co-worker is actually an attractive, young woman.

At first, Marshall is desperate to keep his new colleague a secret from Lily, out of fear that she’ll be upset. But when she does find out of Jenkins’ gender, she is not disappointed or jealous. This actually makes Marshall annoyed that Lily shows no jealously so he starts flirting with Jenkins more and more until they, both inebriated, kiss each other.

Wanting to prove a point, Marshall forces Jenkins to come to the bar so that she can fully apologise to Lily, with orders from Mr Eriksen to not leave out any details. Although Lily seems calm, she proceeds to punch Jenkins in the face before pulverising her on the floor whilst Barney films it and Marshall instantly regrets ever trying to make Lily envious.

It’s meant to be played out for laughs but that was extremely nasty of Lily to brutally attack Jenkins when she was the only one acting maturely, willing to apologise and be completely open and honest about her kiss with Marshall. It leaves the whole episode on a sour note, especially as Amanda Peet's one off character was so enjoyable.