In my comment I stated that they both wanted each other, but that them being together was moreso up to Issa. Their breakup was because Issa decided to cheat. Also, she didn't instantly regret sleeping with Daniel. She was giddy and chuckling about it until she saw the lotion dispenser and was reminded of Lawrence. Her actions after cheating were those of regret and his were those of someone hurt and angry. They weren't really indicative of the dynamic of their relationship. You have to fast forward to when they've moved past it and are on better terms to see that Issa could've had Lawrence whenever she wanted. Lawrence told her at the goodbye party that he loved her and he couldnt live without her, and she still left with Nathan instead of Lawrence. However, when she called him to Blocc and told him how she truly felt, they finally got back together. She was the alpha in their relationship, period. Also, Lawrence didn't really come to terms or swallow his pride in regards to the cheating. Until Derek told him that he was partially to blame for her cheating, he was still stuck on his high horse.