Dianda added: "I got the impression that it is Mel who wears the pants and is the boss in the relationship."
Yet, she went on to admit that Mel had later fallen asleep in their hotel bed, leaving her and Belafonte to embark on another late-night dalliance - which she claims Mel was not bothered about.
"She didn't seem to mind," she finished. "Stephen was really nice and respectful."
The turbulent couple have been at the centre of speculation of an "open marriage" over the last few weeks.
Most recently, Lady Victoria Hervey confirmed swirling rumours that she had enjoyed a threesome with the couple back in 2007.
Addressing the night they spent together, she explained to The Sun that Mel reached out to her via Instagram, adding: "Mel said she just doesn't know if videos exist of that night but she reassured me that they are unlikely to be coming out."
The revelation of the romp had come amid claims by his brother Jeremiah that the shared "a very fun loose open kind of relationship" - which eventually led to the demise of their marriage.
The former Spice Girl filed for divorce from the film producer last month, after 10 years of marriage.
However Mel has reportedly made a huge change to her petition to divorce, asking that she get permanent sole custody of their five-year-old daughter Madison, having previously asked for joint.
TMZ also reports that Mel is now planning to make her temporary restraining order permanent after claiming Belafonte used "racial slurs against her, got the nanny pregnant and was violent towards her in front of the children."
Moreover, they claim that while Mel might allow monitored visits with Madison in the future, she doesn't want Stephen having contact with her other children.
She has Angel, 10, from her romance with Eddie Murphy and Phoenix, 18, from her previous marriage to Jimmy Gulzar.
Mel states in the documents: "I am in fear for my safety and that of my children... Likewise the Respondent's emotional and physical abuse of Petitioner in the presence of the minor child is tantamount to abuse of the minor child."
She continues: "I have tried to leave the Respondent many times. Every time I tried, the Respondent threatened me with violence and threatened to destroy my life in every way.
"He said he would destroy my career and take my kids from me. He threatened to release sexually explicit videotapes claiming I would never again work in the entertainment industry."
Belafonte, 41, has asked for joint legal and physical custody of Madison and is asking for spousal support, the documents show, although no figure is stated.