The King of Queens - Season 8 Episode 9 -

Carrie drags Doug to a karaoke bar and when he gets up on stage he is very nervous, but he starts feeling confident and sings great. When they get home Doug gets an e-mail from a woman that was at the karaoke bar. Doug is at first very flattered, but then the woman begins to send e-mails that makes Doug think that she is stalking him.