Otis is an angel who specializes in patrolling around heaven and finding fallen angels, or high-level demons pretending to be angels and blending into heaven. When he was on patrol, he saw two angels talking to each other, but suddenly the wings of one of the angels turned black, he knew it was a fallen angel. He immediately called the archangel who is also his lover, you. You and I go to the two angels

"oh, a fallen angel?"