Scarlett Johansson is allegedly "incredibly bitter" about Ryan Reynolds marrying Blake Lively.

The Avengers actress - whose divorce from Ryan was finalized in 2011 after four years together - is said to be convinced he cheated on her with the Gossip Girl star while they were still married and was distraught over the couple's recent nuptials.

"Even though there is no evidence behind it, Scarlett has convinced herself that Ryan cheated on her with Blake. She's incredibly bitter about it. In a way, Scarlett feels like Blake actually stole Ryan from her, because it was when he started shooting Green Lantern with Blake in 2010 that everything fell apart," a source told The National Enquirer.

The 27-year-old actress was shocked to discover the couple had thrown a secret wedding reception in South Carolina on September 9 and was especially hurt Ryan remarried so quickly, after only a year of dating Blake. "Ryan and Blake's wedding has brought back a lot of pain for Scarlett. She's sure that Blake deliberately seduced Ryan, even though she knew he was attached at the time. On top of that, she feels like it's a huge slap in the face that Ryan would remarry this fast. Scarlett is happy and dating, but she assumed he would wait a few years before he tied the knot again," the insider added.

Scarlett - who is currently romancing advertising executive Nate Taylor - has spoken candidly about her marriage to Ryan in the past: "It was a beautiful thing. The falling in love and getting married and making that commitment... I think it's nice to know that you're capable of loving somebody in that way. I think it's a rare opportunity."