Michelle Williams and Jason Segel Credit: Michael Loccisano/Getty Images; Christian Augustin/Getty Images

Michelle Williams and Jason Segel are still going strong!

After Us Weekly broke the news of their romance in March, the unlikely pair kept a low-profile while Segel promoted The Five-Year Engagement in Europe and Williams prepped for her Take This Waltz press tour. But on June 19, witnesses saw the couple looking "very lovey-dovey" at Broadway's One Man, Two Guvnors, The New York Post's Page Six reports. Williams, 31, looked "so pretty" in white, while Segel, 32, wore "a suit."

The couple stepped out to support James Corden, 33, Segel's costar in 2010's Gulliver's Travels. "Jason loved the play," a Segel source tells Us. "It was definitely his sense of humor."

According to the source, Williams and Segel "are totally in love. Jason is obsessed with Michelle." What's more, he's become somewhat of a father figure to Williams' daughter Matilda, 6 (with her late ex, Heath Ledger). "He's been doing all sorts of 'dad stuff' with her, like drawing and playing music."

Friends for years via mutual pal Busy Philipps, 32, Segel has only spoken publicly about Williams once, during an April interview with Extra. "I think we would just very much like to be happy," he said. "That's all I'm going to say about it."