Michelle Williams and Jason Segel enjoyed a romantic date night this weekend.

The couple attended the after party for her new film Take This Waltz on Sunday and they apparently couldn't keep their hands off of each other.

Just four days ago they were the same way at an event to celebrate the launch of Jason's new movie The Five-Year Engagement, showing that the couple's relationship is getting serious.

Sources told People magazine that Michelle, 31, arrived about 10 minutes before Jason at Abe & Arthur's in New York.

They were then seen being affectionate the whole night with Michelle touching Jason's head, running her fingers through his hair and flirting and laughing together.

During a funny exchange, Michelle even grabbed him by the shoulders and made him fall on top of her, eyewitnesses said.

Michelle's new movie is about marriage and being in a committed relationship and she plays a wife who battles adulterous temptations.

"I feel like every project grows me up and changes me," Michelle told the publication. "I hadn't quite hit 30 when I made this movie, and to me that's a big part of what this film is about, making that transition and leaving your girlhood behind and becoming a woman."