Are Ashley Olsen and Jason Sudeikis a new couple?

On Monday night, the two were spotted getting cozy at New York City's Stone Rose lounge, according to several reports.

Olsen, 25, and Sudeikis, 36, were on hand to celebrate the release of Ben Stiller's new film, Tower Heist.

Also in attendance at the after-party was Olsen's twin sister, Mary Kate.

Now, sources are saying that it was Mary Kate, not Ashley, who was cozying up to Sudeikis that night.

While Ashley was busy chatting up Brett Ratner, Eddie Murphy and Casey Affleck, Mary-Kate stuck by Jason's side all night long. They were laughing and having a great time together all night. It was cute, a source told E!

Whether it was Ashley or Mary-Kate, the new pairing fits typical Hollywood standards, thanks to the age gap, their differing daytime jobs and their famous past flames.

Sudeikis, a Saturday Night Live regular, was previously linked to January Jones, while Ashley Olsen broke up with her longtime boyfriend Justin Bartha (The Hangover) in March. Olsen has also been romantically linked to cyclist Lance Armstrong. (For the record, Mary-Kate dated Henry Winkler's son, Max, for a few years).

Following Monday's after party, a rep for the Olsen twins shot down romance rumors involving Sudeikis.

Ashley, Mary-Kate and Jason were all at the after party . . . we all hung out together as I work with all of them. That is the extent of it, she told E!

Here is photo tribute to Hollywood's latest rumored couple, Ashley (or Mary-Kate) Olsen and Jason Sudeikis.