Leonard and Penny

Leonard and Penny are the central romantic storyline of The Big Bang Theory, beginning when Leonard is immediately attracted to the aspiring actress and waitress who moves in across the hall. Their first serious relationship starts in the season three premiere, after Leonard returns from a three-month Arctic expedition, but ends when Leonard says he loves her and Penny cannot say it back; Leonard then dates Raj's sister Priya for much of season four. They reconcile, and Leonard's repeated proposals are turned down until Penny herself decides they should marry; they wed in the season nine premiere, after Leonard confesses to kissing a co-worker on the Arctic trip, and later get their own apartment when Sheldon moves out. The finale reveals Penny's pregnancy.