Oh! Duh. Basically she's his hs sweetheart who he was with off/on for most of high school. They broke up once because he came out as being also into men and she was supportive of him exploring that. They got back together but he ended things when he left for the marines. Fast forward all these years and they're super close friends. BFFS even. He's been back now for a few years and is currently a police officer. She's kind of like the #1 woman in his life.