While Amanda is gone, she tries to make Michael jealous, by leaving posts on his Lifeinvader page, saying that Fabien satisfies her physically, emotionally and spiritually.
This hints that Amanda is cheating on Michael with her tennis coach.
She spends his money freely on expensive clothing, jewelry, and plastic surgery, while verbally abusing him. The breakdown in their marriage has also led the couple to have numerous extramarital affairs.
In the mission "Friends Reunited", Trevor comments that Michael bought breast implants for Amanda and made money using her as a prostitute.
This is later confirmed when Michael catches them having sex in his own bed.
Kyle, in panic, jumps out the window to escape, but Michael is determined to catch him.