Trevor was the love of Olivia's life, at least she thought he was. After being single for three years following a relationship that wasn't going anywhere, Olivia was iffy about dating Trevor, out of fear of having her time wasted again. But she and Trevor got along well, and seem to have a lot in common. By their fifth date, she just knew she was ready to give him her all. Before she knew it, they were moved in together and building a life. Trevor seemed so perfect and so attentive to her needs. She knew she had found her prince charming, the one she would marry, have a family with, and grow old together. So it was a shock at first when all of that fell apart. First it was the girls (which would later be the least of her problems), then it was the daughter he had from another women during their relationship. She should've left then, but because she was so in love with him that she thought they could work past that. Then it was the total lack of commitment. She wanted marriage and her own family with him, but he had excuses after excuse to why he couldn't, mostly claiming that the time was never right. What finally made her decide to leave the relationship when she found out that he had been going back and forth between her and another woman. He would spend some nights with her, and some nights with the other woman (claiming he was working late). When she found out about this, she begin packing all his stuff in their apartment. Because Trevor wasn't happy about that, he proceeded to talk down about her, insulting everything he once loved about her. Then he leaves her alone.
"It's easy for someone to say "Get over it" when they don't realize how much something has destroyed a person. That's what everyone told her about Trevor, that she should get over him. It was easy for everyone to say that because they didn't get treated by him the way he treated her. 'Talk to me when you're told you're nothing by the same pair of lips that once held love for you,' she would tell them when they gave her that line. Wendy was the worse. because she was mutual friends with both of them, she tried not to take sides, but obviously Wendy sided with Trevor because Wendy was dating Trevor three months later, her reasoning, 'Just because he treated Olivia that way, doesn't mean he was gonna treat her that way.'"
Her break up with Trevor started her drinking because she used to drink to settle her nerves while she was dating him, and then she drank more to soothe her broken heart as well as her angry resentment she felt towards him.