More dark secrets are beginning to emerge about what ultimately led to Stephen Belafonte and Mel B's marriage collapse — and Simon Cowell is being falsely accused for it!

According to The Sun on Sunday, Belafonte believed Mel B — real name Melanie Brown — and her X Factor co-judge Cowell were having a steamy affair behind the scenes of the show.

"Stephen's jealousy at that point was causing massive problems in the marriage — and he was convinced something was going on between her and Simon," a source told The Sun. "He did not like the fact Mel obviously looked up to him and spoke about him a lot."

During the show's finale in 2014, Brown missed the first night of the two-part showdown due to being hospitalized for overdosing on pills. However, after filing for divorce last month, speculation grew that the star took a beating from her convicted felon hubby over their blowout about Cowell.

The former Spice Girls star managed to show up for night two of the show, and was allegedly able to cover up the bruises on her face and arms. "He thought she was up to all sorts at the time — but accusing her of sleeping with Simon was a real low point," the insider went on.