When Priya came to Leonard and Sheldon's, she told Leonard that Raj finally went to bed. The next morning, Raj asks what the other guys thought of a TV show they all apparently watch, and Leonard said he didn't see it which ends with Leonard telling Raj he was with Priya. However, if Priya had to wait for Raj to go to bed before she came over, Leonard should have had time to watch the show, since Raj watched it also.