You're the biological child of Simon "Ghost" Riley.
You weren't planned. A decade and a half ago, he had a one-night-stand with a woman whose face he couldn't remember in the morning. He didn't particularly enjoy it. It was back when he was still denying his own sexuality, and before he had met his now-husband, Johnny "Soap" MacTavish. He never knew that there was an unknown consequence.
However, when your neglectful mother drops you off at the military base where Ghost lives, he's forced to confront the irresponsibleness of his younger self and become a parent. He now has legal custody of you. All you had when your mother abandoned you was a trash sack filled with some clothes and toys.
Your life changes for the better. Now you live in Simon and Johnny’s on-base home, and you’ve made plenty of friends with the other military-raised kids. You’re expected to hold yourself to a high standard of respect and discipline, but your new fathers aren’t cruel or mean. They take the time to try and understand who you really are, instead of just enforcing rules blindly. It was all a little weird in the beginning. You were scared and uncertain. You were surprised to find that your father had a husband, but Johnny, to his credit, took to you immediately. You become the Scotsman's little partner-in-crime. Simon is more broody. He’s scared of turning into the kind of parent his own father was, and so he walks on eggshells. He doesn’t speak often, but when he does, it’s meaningful. Slowly, he learns to unwind. You and he are on good terms.
As you grow older, you begin to branch out with a personality and tastes of your own. You experiment with your style, get into new hobbies and interests. And one of those style choices is that to bleach your hair... while your dads are away on a mission.
They come home exhausted, sweaty, caked in mud and dirt and bodies still wound tight from the stress of the op. In hindsight, maybe it wasn't the best idea to show your new appearance off.
Simon halts in his tracks, his Kevlar vest halfway off and his balaclava pushed up. Johnny stops beside him.
"Och, henny, wha' did ye do tae ye hair?" the sergeant exclaims. Simon just stares.
"So... do you like it?" You ask hesitantly, your hair now a whitish corn-silk blonde. You used to have dirty-blonde hair, exactly like Simon's. You look like Simon a lot, actually, with the same dark hazel eyes and pale skin, the same square jaw. It's something that worries Simon constantly, because if you look like him, you might turn out like him-- broken.
But now you look like him a little less.