Orange is the New Black stars Laura Prepon and Samira Wiley are engaged to their respective partners

Laura Prepon and Ben Foster are engaged afetr dating since July. Photo / AP

Something's in the water at Litchfield. Two Orange is the New Black stars are reportedly engaged to their respective partners after whirlwind romances.

Many may not have even been aware that former That 70s Show star Laura Prepon was dating actor Ben Foster, who only recently was engaged to House of Cards star Robin Wright.

However Prepon and Foster made their red carpet debut at the premiere of Prepon's new film, The Girl on the Train overnight and the 36-year-old was sporting a flashy diamond on her ring finger.

#GOTT #Premiere! TY glam: @tinaturnbowmup @josueperezhair @nhakahn @forevermarkdiamonds @hellinkay 4 my look! #girlonthetrainmovie pic.twitter.com/C4HgQW3iV8

— Laura Prepon (@LauraPrepon) October 5, 2016

Sources confirmed to People magazine that the pair are engaged despite the fact they only started dating in July.

The magazine says despite the quickie engagement, Prepon has known Foster, 35, since she was 18. He is best friends with her former That 70s Show co-star Danny Masterson.

Prepon dated Masterson's brother, Malcolm in the Middle star Chris Masterson, for seven years before they split up.

The Mastersons and Prepon are well-known Scientologists however while Foster is friends with many people connected to the church it is unclear if he is also a member.

Prepon's news came as co-star Samira Wiley confirmed that she and Orange is the New Black writer Lauren Morelli are engaged.

View this post on Instagram

Yes.

A post shared by Samira Wiley (@whododatlikedat) on Oct 4, 2016 at 9:08am PDT

The 29-year-old, who plays Poussey Washington in the prison show, started dating in 2014 when Morelli divorced her husband of two years, Steve Basilone, after she fell in love with Wiley on set.

Wiley posted an image of the couple to her Instagram, showing off her sparkler and captioning the image 'yes'.

The cast from the television show Orange is the New Black.