Back in October 2013, Glee star Rivera and Rapper Big Sean got engaged, but went through a messy public split in April 2014 with the engagement called off. . In October 2014, the rapper and Grande confirmed they were dating, but after about eight months together, they called it quits. According to Rivera, though, the “Side to Side” singer and hip-hop artist’s romance may have been blooming while she and Big Sean were still together. Here’s how it all went down: Like all relationships, Rivera and Big Sean had their arguments. “We’d been fighting for five straight days while he was travelling, and then on the one day that he was back in L.A., he said he didn’t want to see me,” she wrote in her book. “Well, a**hole, I’ve got a key to your house.” When she got to the rapper’s house, she wasn’t impressed with what she saw. “I walk in, go downstairs, and guess what little girl is sitting cross-legged on the couch listening to music?…” she...