'The Big Bang Theory' recap: Past hook-up haunts Penny

Raj's honesty about his past comes back to haunt him after his girlfriend, Emily, is cold to Penny (Kaley Cuoco-Sweeting, left, with Mayim Bialik) (Sonja Flemming/CBS) (�©2014 CBS Broadcasting, Inc. All Rights Reserved.)

The gang hangs out with Raj’s dermatologist girlfriend Emily for the first time all season. She seems to fit in with the crew quite easily, with one exception. Penny gets the vibe that Emily isn’t that into her. After some encouraging from Bernadette, Penny makes her way over to Emily’s office to practice for her new job in pharmaceutical sales.

Penny gives it her all, but Emily can barely be bothered to make eye contact. When Penny finally asks what gives, Emily gives it to her straight: She knows about her past hook up with Raj. Penny swears it wasn’t a hook up, but after confirming that they did indeed kiss and get naked, she ends up digging the hole even deeper.

This is especially difficult for Penny, who explains that no one has blatantly admitted to disliking her before. “We have lived very different lives,” Amy deadpans after listening to her confession.

After getting reamed out by Penny for telling his new girlfriend about their hook up, Raj sets up a meeting between the two women. They talk it out and even agree to set up a double date in the near future. With big smiles and even bigger hugs, they part ways only to declare “I hate her,” in unison just as soon as they’re out of earshot.

The guys are disappointed to learn that Stuart didn’t receive enough money from the insurance company to reopen the comic book store after it burned down. Growing increasingly frustrated with the new comic book store they’re forced to shop at, the gang hatch a plan to pool their resources and invest in building a new shop.

Sheldon has plenty of ideas about how the new shop can crush the competition, which include everything from spreading rumors about genital warts to using candy to lure children into a van that will taken them straight to the comic shop.

While Amy reluctantly supports Sheldon and Penny gives Leonard her blessing (though her massive debt confession should cause him to rethink), Bernadette does not cave so easily. It’s only after some prodding that she and Howard go to Stuart, still living with Howard’s mother, to tell him they’d like to invest.

As it turns out, however, their contribution won’t be necessary, as Stuart already has the money necessary to reopen. But who fronted the cash? Much to Howard’s dismay, none other than his mother, Mrs. Wolowitz!