Elizabeth Plimpton was a very minor but memorable character on the show. She was a doctor of some sort, but I forget what she actually practiced.
At first Leonard thinks he’s found a new girlfriend.
And it becomes obvious that she’s definitely okay with the physical side of the bedroom.
But it turns out that she is very very promiscuous and invited Raj, Howard, and Leonard to take turns on her at once. They all chicken out, except Raj, which I think it was his apartment anyway. I don’t hate the character for being so open, as a lot of the guys on Big Bang Theory have done or would have done worse things, given the chance. She was just poorly written and only created for one silly plot line.