The Grasshopper Experiment
The Big Bang Theory Season 1 Episode 8 (11/12/07)
Raj is scared when his parents arrange a blind date for him with a girl from his childhood as he's still unable to women. However, when Penny takes up bar tending to make some extra money and practices on the guys, they discover that after a few drinks Koothrappali can talk to women. On his date at Penny's restaurant (with all the guys watching), he becomes obnoxious and Sheldon accidentally steps in and compliments the girl and she ends up leaving with him.
Raj and Leonard go back to Leonard's apartment and Raj tries to explain over teleconfrence to his parents what happened. His parents get even madder when they find out he's been drinking. Sheldon returns and when questioned by Leonard, he doesn't consider his night with her a date.