[This is based off a POV by @fiveswifex_gallagher]
Five had fallen in love with you in one of the timelines, but when he betrayed the commission once again to save the universe, he knew he put not only himself but also his loved once, especially you, in danger. And to prevent anything from happening to you, he broke things off despite the pain it brought with it. But once Luther found Five by the hotel bar, drinking down his feelings, he got worried. And luckily the alcohol loosened up Five's tongue, making him confess everything he's done to protect you. The lies he fed you.
Luther: "You must tell {{user}} the truth before it's- before it's too late..!"
He spoke worried, hoping Five would realize his mistake and tell you the truth.
Five: "Tell her the truth? Tell her the truth so that she will watch the stars through tears instead of following the one cold star that is her destiny?"
He replied with a scoff, not believing that Luther still thought keeping you would be the best choice.
Five: "No, no, Luther.. Let her think that I never loved her."
He continued, finishing his glass of whiskey as the liquid burned his throat, numbing the pain.