Photographs taken by US weekly would suggest that long-time friends Michelle Williams and Jason Segel, are dating 

The duo were spotted walking arm-in-arm in Brooklyn and later Segel was snapped playing with Mathilda, the daughter of Williams and the late Heath Ledger.

The A week with Marilyn and How I met Your Mother stars were introduced through William's best friend, Busy Philipp's, according to US Weekly, and have been close friends ever since.

They're much more serious than everybody thinks . . . They're really happy, an unnamed source told US Weekly.

Neither Williams's nor Segal's reps have confirmed that the duo are dating, but the photos have spoken for themselves and rumors have been circulating fast.

A source told US Weekly that the couple is determined to make their relationship work even though they live on opposite coasts.

William's most famous ex was the late Heath Ledger, who she spilt from five months before his death. Since then she has dated directors Spike Jonez and Cary Fukunaga.  

Reactions

On Twitter fans have been set abuzz by the rumors surrounding the alleged new couple. So I just want Michelle Williams and Jason Segal to get married. It'll be perfect, Amelia tweeted.

Michelle Williams and Jason Segal as a couple makes me so happy-too awesome people, seems like a perfect match, Srimathi Sridhar Tweeted.

Here are 3 reasons why they would make a great couple:

Character: Both come across as being shy and humble. It's seems fame hasn't gone to either one's head, allowing them to lead a down to earth, less pretentious life.

Kids: Judging from the photograph of Segel interacting with William's daughter, it seems he is great with kids, which is imperative if he pursues a relationship with Williams.

Adorability: Both have been dubbed two of Hollywood's most adorable characters. During an appearance on Craig Fergusion Segal said the biggest thing he missed about having a partner was cuddling.