Demi Moore and Ashton Kutcher
Kutcher is a problematic person because he seduced an underage Mila Kunis and defended a convicted rapist. But before that, he married Moore and had a six-year marriage. After they finally divorced, Moore spilled the beans in her memoir. She aired their dirty laundry in public as she showed his reportedly abusive antics.
Moore said that he coerced her into threesomes against her will. She acquiesced because she wanted to please him but felt shame. Meanwhile, he also allegedly used these experiences to justify cheating on her. It made their relationship very toxic and uncomfortable for her (via The Mercury News).