CBS

Season 7: Episode 2 - The Deception Verification

The Deception Verification: Leonard surprises Penny by coming back from his research expedition early, but he wants to keep it secret from everyone else to spend some alone time with her. Sheldon figures out that Leonard came back without telling him, however, and gets very upset. Meanwhile, Howard has been acting snippy and sensitive lately, and Bernadette eventually figures out that it's due to the estrogen cream he's been rubbing on his mother.