The fun part of being a long-running sitcom about people dating in their 20s is that the show has the perfect opportunity for regular stunt casting. "How I Met Your Mother" could accidentally threw Britney Spears in an episode or two without messing with the format, just like "Seinfeld" can get Keith Hernandez to stand with Elaine for an episode. Of course, not every celebrity guest star is as big as Spears was, but even a small star can still help bring in additional viewers.

A case in point was the Season 3 episode of Friends, "The One with Frank Jr.," in which Isabella Rossellini stops by the gang's coffee shop, playing herself. The central joke here is that Ross (David Schwimmer) originally put Rossellini on his list of famous women he could sleep with without his girlfriend Rachel (Jennifer Aniston) getting upset about it. However, Ross decided to drop Rossellini from the list, deeming the Italian actress less likely to be in the neighborhood than someone like Winona Ryder. Sure enough, the moment Ross bumps into Rossellini, the actress shows up, leaving Ross frustrated by the bad timing.

Luckily for him, Rachel believes she doesn't have a shot of the movie star, so Ross still gets his chance to shoot his shot, but it goes badly. The whole sequence was great for Rossellini fans, but the actress herself was a little uncomfortable with the whole thing. In a recent interview promoting her new film Conclave, she explained why she wasn't sure if the joke would work with American viewers:

“I was surprised because at the time—maybe still today, but maybe to a lesser extent at the time—there weren't many foreign actors who were recognized in America. And that's why I was very surprised that my friends invited me, not only as a guest, but as a star they recognize me and know my name... Am I really famous that I can play as a famous person? So that was really great and it was a pleasure to work with them."

Although a teenage critic from The Burlington Free Press was strangely angry about the storyOverall, Friends fans seem happy with the story. "Isabella Rossellini's cameo is one of the series' best," wrote The Daily Beast in recent ranking from each episode. "Independent", on the other hand, ranked "The One with Frank Jr." like on the show the ninth best episode sometime. If you search through the Friends subreddit, you'll find no shortage of love for the scene where Ross tries to flirt with the star.

I think that's the reason the whole scene works so well, even on viewers who aren't familiar Rossellini's excellent performance in films such as Blue Velvet, is that viewers don't actually need to know anything about her to understand. All they need to know is that she's a famous actress who's widely agreed to be attractive, all covered up by Ross and Chandler before she's on screen.

Similarly, the scene where Ross digs Rossellini is funny for the same reason that any scene in which Ross awkwardly bumps into an attractive woman would be funny to watch; her celebrity status simply adds to the humiliation for him. The sequence strikes a fine balance between giving Rossellini fans enough material to make it clear that the series has done their research, while also ensuring that regular viewers (and future viewers) can appreciate everything well.

In the end, Rossellini had nothing to worry about. Although every viewer should ideally she would be familiar with her work, the Friends writers were smart enough not to make that a requirement. "The one with Frank Jr." is a great episode of one of the best sitcoms of all timeand Rossellini was the best part of it.