AceShowbiz -

Words are, comedienne Sarah Silverman is dating "Masters of Sex" star Michael Sheen. The duo were seen making out in West Hollywood on Thursday, February 6, prompting rumor that they have embarked on a new romance.

According to Us Weekly's source, Silverman and Sheen were hot and heavy at Soho House. "They were all over each other for a lot of the night," the eyewitness claimed.

Rumors started when Silverman attended the British actor's 45th birthday party in West Hollywood. Together with other celebrities including Sheen's ex-wife Kate Beckinsale and her current husband Len Wiseman, Silverman partied the night away at Craig's. "Sarah and Michael came and left together. She drove," an insider told Us. "When they left, Sarah opened her trunk so Michael could put all of his gifts in and then they drove away."

Silverman previously dated talk show host Jimmy Kimmel for five years and split from him in 2009. They remain friendly. Sheen is also in civil term with Beckinsale whom he married for eight years and has 14-year-old daughter Lily with. The former couple walked the red carpet of a Golden Globe after party together with Wiseman on January 12.