Sheldon Cooper loves contracts. He’s been writing them since kindergarten, so naturally he jumped at the chance to have his best friend document their new business relationship by signing on the dotted line.

Remember a few weeks back when Sheldon got hammered and came up with some great new invention? Now, the whatever-the-heck-it-is that Leonard and Howard helped him create is up for a patent.

But problems arise when their attorney informs them that CalTech will get to keep 75 percent of the profits. Worse yet, Howard — because he is a NASA employee — gets nothing.

So the guys cook up a plan to cut him in on the action. Sheldon and Leonard agree to form a partnership and share the proceeds equally with their friend. That is, until the ladies catch wind of the proposed deal and caution Howard against signing anything without having a lawyer review it first.

Bernadette:  “You are about to form a legal partnership with Sheldon Cooper.”

Howard:  “If you are going to calmly make excellent points, then I don’t want to talk to you.”

The compromise:  Sheldon must agree in writing to refrain from making fun of Howard, including mocking his belief that “Ghostrider” was not a bad movie.

“Any contract I sign is enforced with my own personal code of ethics,” Sheldon assures everyone.

“And his obsessive compulsive disorder,” Amy adds.

When the revised document is given to the group for approval it contains a surprise no one saw coming:  the additional stipulation that part of Sheldon’s share will go to establish a college fund for Howard’s unborn baby.

Meanwhile, Raj is trying to figure out which woman to spend the night with.

Early in the episode he received a $500 gift from ex-girlfriend Emily, an almost certain sign that she wants to get back together. But Raj has had his eye on flirty bartender Claire for weeks, and now she has broken up with her boyfriend and is looking for a good time.

Emily calls to say she is upset and needs a friend, prompting Raj to jump in his car and head to her house.  But then Claire calls looking to hook up.

We go back and forth a few times, but in the final frames, Raj end up in bed with ... wait for it ... Emily!

We’ll have to wait a week to find out what happens next.

"The Big Bang Theory" airs Thursdays on CBS.