In the all new episode of "Grey's Anatomy" season 11, spoilers revealed that the upcoming episode would focus on Derek and Meredith's martial problems.

On the hit medical drama, troubled waters hit the season's most secured couple when Meredith called Derek and a woman answered which drives her to suspect that Derek is cheating on her.

"Grey's Antomy" season 11 spoilers from IB Times teased that Derek might have been unfaithful to Meredith. The promotional video also hints that Derek may have (or may not have) a relationship with Renee Collier, his new resident. Renee Collier, played by Scottie Thompson, is seen holding the hands of Derek and passing him some teasing glances.

The episode last week provided answers to the couple's situation. Derek, not taking the early flight, went straight to Merideth's apartment in the middle of the night as he explained why a woman answered her phone and told her that they're in trouble.

According to the official synopsis of "Grey's Anatomy" season 11, episode 17 called "With or Without you," Derek will explain his side of the story but it seems that Merideth is not interested with his explanations.

The full synopsis of episode 17 reads as follows:

"Meredith is unnerved by recent events and is unsure about how to proceed with Derek. Elsewhere, Owen is surprised when his mom becomes a patient at the hospital."

While the sneak peak of the episode implies Derek having a secret affair, CaterMatt reports that part of Derek wants to yet at the last minute stops himself. This may explain why he went to Meredith's apartment in the middle of the night. Callie, however, is doubtful of Derek's sincerity when he showed up in Meredith's doorstep without warning.

Is Derek cheating on Meredith? Find the answers in the next episode of "Grey's Anatomy" this Thursday, March 26 at 8PM ET on ABC.

Tune in for more "Grey's Anatomy" spoilers, recaps and cast updates.