Directed by: Mark Cendrowski
Written by: Steven Molaro
Original air date: September 21, 2o09
When the men return home from their expedition at the Magnetic North Pole, Penny reveals her feelings for Leonard and kisses him when he visits her. Both are interrupted when Sheldon is humiliated on learning that Leonard, Howard and Raj tampered with one of his experiments, and retreats to his mother’s home in Galveston, Texas. When Leonard arrives in Texas, it is Mary who convinces Sheldon to forgive him by disagreeing with his views on evolution. Leonard and Penny then finally have sex, but concede that things are now weird between them.