Season 4, Episode 13 - The Love Car Displacement
Aired January 20, 2011
When the gang stays in a hotel for a science conference, Howard and Bernadette have an argument after she runs into her ex-boyfriend which causes a ripple effect throughout the group.
Season 6, Episode 23 - The Love Spell Potential
Aired May 9, 2013
After the girls' trip to Vegas goes awry, they join the guys for a game of Dungeons and Dragons, which takes Sheldon and Amy's relationship to an unexpected place. Meanwhile, Raj and Lucy have a very awkward date