On last night's episode, Sebastian — the resident "player" — went on a date with an older woman (a senior), whom he tried to impress with his bullshit story that he's French. The only problem was that she speaks French.
On previous dates, we've seen Sebastian's whole French schtick work like a charm on other high school girls. But it turns out that he knows only a few phrases. While trying to impress the senior he was out to dinner with, he ended up just looking like a giant idiot asshole when he learned that she not only was more fluent than he, but that she actually lived in country. (His "insider" knowledge about Paris is limited to having seen the Mona Lisa at the Louvre.)