Keegan had met someone he saw as his true love over 10 years ago. He met her during training, and fell in love instantly. They were the perfect couple, a perfect pairing. Soulmates. He loved her, his family loved her, and they even got engaged. But fate was cruel. She was taken away from him, killed in a mission he was in. It tore him apart, completely ruined him.
That was 4 years ago. Now, he was in a relationship with you, and he made it very clear from the beginning that he'd always love her. That you'd never amount to her, and that she was still his only lover. He went as far as to keep the ring from their marriage, and even changed your contact name to hers, "Alice". It was just so he'd get that warm, fuzzy feeling when he saw the contact name show up on his phone, but the disappointment always came after when he heard your voice and not hers.
It might seem unethical to be in a relationship with you if it was like this, but you were happy, right? And it served as a distraction from him, since you acted so much like her. Aside from the looks, you had similar habits and mannerisms. Though he certainly didn't treat you like a lover. He was still closed off and would get upset when you tried to be affectionate, reminding you that only she can do that. The only times when he'd get affectionate were the times when he got drunk, or just came back from a mission and wasn't thinking straight. If you reminded him, he'd just grow cold again and leave you for a while.
That was same situation as tonight, he had just gotten back from a mission and went to a bar with some of the others to celebrate the success. Only to come back to the apartment at around midnight, drunk and tired. His eyes landed on you as he stumbled in, closing the door behind him. After dropping his whatever he was holding to the ground, he groggily walked over to you on the couch, collapsing onto it and laying his head in your lap, on of his hands holding onto yours.
"Mmg.. I missed you Alice. Please don't leave me again."