Marshall and Lily met in college. It was love at first sight. They dated and even got engaged but Lily called it off, moving to San Francisco to focus on her artistic interests. They were separated for six months due to this, finally getting back together a few months after Lily's return to New York, and getting re-engaged then married. Eventually, they found out that Lily was pregnant, and she gave birth to a boy named Marvin Wait-for-it Eriksen.
While devoted to each other, they have had to overcome their share of challenges, such as Lily's credit card debt and dislike of Marshall's mother, and Marshall's occasional workaholic tendencies that keeps him from having sex with her.
The Scorpion and the Toad - Marshall and Lily are reunited. Lily wanted to get back together, but Marshall decides not to, considering she left him before.
Brunch - Sexual tension between the two as they live life apart.
How I Met Everyone Else - Marshall and Lily's first meeting. It may have been tainted by the true story of how Lily and Ted met.
Dowisetrepla - Marshall and Lily want to buy an apartment but they are hindered when Marshall learns that Lily has been hiding a massive credit card debt.
Everything Must Go - Marshall wants Lily to sell her clothes to help pay to repair the floors in their new apartment but he is skeptical when she wants to sell her paintings instead.
The Magician's Code - Part Two - Robin is appointed by Marshall and Lily to take the photograph for baby Marvin's birth announcement, but she can't take a decent shot of the three of them together. Eventually the two fall asleep on their bed with Marvin between them, allowing Robin to get a perfect if unconventional shot.
No Questions Asked - Marshall tells Lilly about his new job as a judge, ruining their plans to move to Rome for a year
Unpause - Marshall and Lilly "unpause" their fight about Rome, however Lilly runs away half way through and gets picked up by a mystery person.
Sunrise - Marshall and Lilly make up and agree to star in New York
Daisy - Lilly reveals that she went to The Captain after Marshall and Lilly's fight in Unpause because she thought she was pregnant. Marshal and Lilly find out that Lilly is pregnant and decide to move to Rome to give Lilly her dream because she has already given Marshall his dream, twice. (Marvin W. Eriksen and Daisy Eriksen)
Marshall and Lily have an extremely adventurous sex life particularly when it comes to roleplaying games. We see Marshall dressed as Fay Wray and tied to his bed whilst Lily enters dressed as King Kong and it is suggested they also roleplay Lily being a prostitute, when Marshall comments that Lily should 'sell your stuff' (meaning her artwork)she replies 'Baby that's just a game we play in the bedroom'. It is hinted they also experiment with S&M although we are told Marshall is reluctant to spank Lily forcefully.
