Last month, I was out of town for my little brother's wedding and stayed in a hotel room. You know how it is in hotel rooms -- late at night, you watch things on TV that you wouldn't bother with at any other time. My husband and I ended up watching part of Eurotrip, a rather lame comedy from 2004 about a couple of guys who travel to Europe so one of them can make nice with his longtime (female) pen pal.
I fell asleep fairly quickly, but not before watching a memorable scene with a cruelly comic song that reveals the main character's girlfriend is cheating on him. The song is called "Scotty Doesn't Know," and since the main character is named Scotty ... you get the idea. The lead singer looked oddly familiar, but it wasn't until later that I learned it was Matt Damon. Admittedly, Damon's singing voice is dubbed by the real lead singer of the band performing the song, Lustra. Also, we don't usually see Damon with a shaved head, chin piercing and a tattoo on his neck. An IFC article about Damon's numerous cameos in film claims Eurotrip was shooting in Hungary while Damon was there for The Brothers Grimm, and the Eurotrip filmmakers convinced him to appear in their film too.
YouTube has a clip from Eurotrip of "Scotty Doesn't Know" that includes Matt Damon's highly energetic performance, embedded below. In all clips of this scene that I found on YouTube, the front of Damon's shirt looks intentionally blurred so you can't see what's printed on it. I thought it would be something incredibly nasty, but when I found the above still, the shirt read "Get Off My Case." I suppose it's just a loss in quality on YouTube videos, and I'm slightly disappointed. The lyrics of the song, however, are definitely R-rated, just to warn you.