It takes an inordinate amount of wit and charm to best Conan O’Brien in a riff-off. The most an average comedian or host can hope for is not to embarrass themselves trying, which is largely how Kareem Rahma fared in a recent episode of his popular social-media series, Subway Takes. But toward the end of the interview, Rahma and O’Brien were shown up by a stranger named Debbie Shields who just so happened to be commuting on their train. The 68-year old native New Yorker didn’t know what ‘SubwayTakes’ was, or that she was about to get pulled into a viral improvisational comedy bit. But thanks to a childhood spent performing in church and experience hosting comedy and karaoke nights, she says her instincts kicked in immediately. This 'SubwayTakes' appearance isn’t even the first time she has been put on the spot by someone with a huge comedy platform. Shields shares which comedian once pulled her onstage at Barclays Center, how she’s handling her virality, and whether she’d be interested in hosting a show of her own: nymag.visitlink.me/Tr0FRD