Meredith (Ellen Pompeo) just became the host to the world’s most awkward dinner party ever. In episode 5 of “Grey’s Anatomy,” titled “Look Who’s Coming To Dinner,” Mer will be forced to break bread with the woman who killed her husband. And as you can imagine, the cringe-worthy situation just doesn’t sit well with the widow -- literally.

In a promo video for the upcoming installment, fans watch Mer as she gets the urge to vomit after seeing the face of Callie’s (Sara Ramirez) new girlfriend, Penny (Samantha Sloyan). Penny was the doctor tasked with keeping Derek (Patrick Dempsey) alive in Season 11 of “Grey’s Anatomy” following his life-threatening car crash. But ultimately, the surgeon failed to save the beloved McDreamy.

Feeling sick to her stomach at the sight of Penny, Mer races to the bathroom -- an alarming scene that Alex (Justin Chambers) just so happens to witness. But Mer only acts stranger as the dinner party continues -- smiling incessantly, anxiously tapping her fingers. In a sneak-peek video for episode 5, Alex confronts Mer about her suspicious behavior.

“What’s going on? Are you alright?” he asks his “person,” who responds that she’s “great.”

“You’re not great,” Alex rebuttals, noting that he can tell Mer is “freaked out.” “Something’s wrong.”

And while we’re glad Alex has noticed there’s something off, we’re curious how he will piece together that the reason Meredith is acting peculiar is because Callie is dating the woman who let Derek die.

In episode 4 of “Grey’s Anatomy,” Meredith explained to the interns (after they were tasked with being the ones to reveal to family members that a loved one had died) that they need to take their jobs seriously.

“You are changing this person’s life forever. You are responsible for this moment,” she advised, reminding the newbies that their faces will forever be etched into the minds of those families -- just like Penny’s face was burnt into her memory.

Will Meredith reveal Penny’s identity in episode 5 of “Grey’s Anatomy”? Find out when the medical drama airs on Thursday, Oct. 22, at 8 p.m. EDT on ABC.