Comedienne Sarah Silverman is joining her rumoured beau Michael Sheen on his popular drama Masters Of Sex.

Silverman has been cast in a recurring role for the upcoming sophomore season of the period drama, which stars Sheen and Lizzy Caplan as two pioneering researchers of human sexuality.

However, the funnywoman won't have too much screen time with Sheen, as she's slated to play Helen, a closeted lesbian and former lover of one of the female participants in his study, according to

Silverman has been linked to Sheen since February (14) but they have kept mum on their romance.

Sheen previously dated actresses Kate Beckinsale and Rachel MCAdams, while Silverman has romanced talk show host Jimmy Kimmel.

The second season of Masters of Sex is set to kick off in America on 13 July (14).