'Big Bang Theory' Season 8 Spoilers: Amy and Sheldon Get Set to Start a Family

Thursday's episode of "The Big Bang Theory," titled "The Colonization Application" will see Sheldon and Amy deciding to take their relationship to the next level by adopting a pet. The duo will decide to get a turtle as Sheldon isn't too fond of dogs.

However, the self-centred Sheldon will ruin this big moment for Amy when he reveals that he plans to relocate to Mars and has even applied to be one of the first humans to be sent there.

According to the extended plot synopsis on "The Big Bang Theory" wikia page, Amy and Sheldon will return from the pet store empty handed after Sheldon's big reveal and not surprisingly, Amy isn't happy with the announcement. Sheldon has once again taken a decision without consulting her, and it seems like Amy will question her decision to be involved with Sheldon.

The characters of Amy and Sheldon, affectionately called Shamy, have come a long way since getting together, and "The Colonization Application" will see the duo achieve yet another milestone in their relationship.

Over the years they have been together, the couple has kissed, and even professed their love for one another. And although Amy has seen Sheldon naked, there has been no movement with respect to their sexual relationship.When questioned about when Shamy will achieve their next milestone, Steve Molaro, executive producer and "The Big Bang Theory" showrunner told TVLine that they don't usually plan anything beforehand.

"These characters are living, breathing people to me, so I try not to think of them in terms of a check list. To be honest, we didn't even know the 'I love you' was going to happen until we were in the middle of figuring out the prom story. So I'd like to think there are even more milestones, beyond the bigger more obvious ones, that haven't even occurred to us yet."

As for their sexual relationship, Molaro said: "I have no idea when that will be broached, but I have learned that if we're sweating and scared of a scene, that's usually a good sign to do it."

"The Big Bang Theory" airs Thursdays on CBS. The official synopsis of episode 17 reads: "Amy and Sheldon decide to get a turtle together, while Sheldon is planning on going to Mars. Leonard and Penny don't want to be a boring couple and Raj is snooping around Emily's apartment."