"How I Met Your Mother" Season 9 episode 4 will be airing tonight on CBS at 8 p.m.

If you miss tonight's episode, be sure to watch it online via live stream on the CBS here.  It can also be viewed via iTunes or Amazon Instant Video.

The official synopsis for "How I Met Your Mother" season 9 episode 4 titled "The Broken Code" is as follows: "While Barney works through his anger at Ted after finding out he still has feelings for Robin, Marshall Skypes in to act as a judge and help settle their dispute. Meanwhile, Lily realizes she is Robin's only girlfriend."

In new sneak peek clips released by CBS, Barney finally confronts his friend Ted after catching him holding hands with his fiancee Robin. Last week's episode ended, viewers saw that Barney knew about Ted's feelings for Robin.

In tonight's episode, Lily will also discover that she is Robin's only girlfriend.

The final season of the popular comedy series will finally reveal more details about the mother and how she came to meet Ted Mosby. After years of telling his kids stories of his life, friends and love life, Season 9 will finally allow viewers to get to know the mother. The season takes place over the course of Barney and Robin's wedding weekend with everyone's lives changing at the same time - Marshall and Lily prepare to move to Rome; Ted prepares his move to Chicago; Robin and Barney tie the knot.