Lily Aldrin enacted the role of Alyson Hannigan in the nine-season long sitcom, How I met Your Mother. However, she had disappeared from a few episodes in season four. Her disappearance raised many questions. Pregnancy and conflict of interests are the two stories that gained traction over a while. Lily played the lead role in How I met your Mother and met Ted Mosby, on the show, which prompted her to befriend her future husband, Marshall Eriksen. Keep scrolling to know why Lily has disappeared from the show and what the writers had offered to the audience regarding her absence in the show.

By the time season 4 began Marshall and Hannigan (Lily) were already enacting the roles of a married couple. And Marshall was shown as a character struggling with his career all throughout the season four. He fails to land his dream job, an environmental lawyer, and settles for a corporate position. The season runs a parallel story despite the struggle Marshall is going through throughout the season. The budding couple shares their views on becoming parents in this season at the beginning of the season.

Lily started to disappear from the 20th episode of season four and makes her reappearance in episode 23 with the title “As fast as she can.” The reason offered to the viewers for the disappearance of Lily was Hannigan’s maternity leave. Lily has taken a break in 2009 to give birth to her first baby girl. This is the reason Lily is not seen in a couple of episodes from the show before she finally makes a quick comeback in episode 23. The show makers adopted a rather funniest way to explain the absence of Lily in the show.

During the beginning of season 4, Berney tries to share a joke with Lilly, Hannigan. Ted and Marshall interrupt them and warn that the joke is “guy funny.” And Ted again warns that the joke is the dirtiest one he had ever listened to. Upon the turn of events following this scene, Lily walks away from the group and avoids them for the next month. This line was added by the makers to cleverly explain things why Lily was away for the few episodes in the season. Robin Scherbatsky's role was played by Cobie Smulders and she was also pregnant around the same time before all this has happened.

Lily can be seen only in the final episodes of the season after her quick comeback. After she meets her friends once again, she claims that it indeed was a dirty joke but was also a funny one. Then Barney says something more offensive which prompts Lily to walk away again but this time Lily doesn’t disappear from the show. The actress has been called a strong lady when she makes her come back just days after her first labor. She didn’t take her maternity leave during her second pregnancy too in 2012. Her pregnancy was included in the show to keep her in the show. This is when Marvin Eriksen comes into the show as the first child of Lily and Marshall.