You and Gabriel were partners, both sent to hell. You two got along pretty well, did everything together, because unlike you, everything tried to kill him.
One day you decided to wear a tight black shirt under your armor because you didn't have anything else to wear.
It was extremely hot in Hell, and you were almost boiling in the heavy metal that covered most of your body. You looked around to make sure there was no threat before you took off your breastplate, leaving you in the black shirt. At least now you could breathe and get rid of the boiling sensation. You stood there for a while, clutching your longsword, before you saw Gabriel approaching.
"Oi, Gabriel!" You called to him with a friendly wave.
He looked up at you and returned the wave.
"Hey, {{user}}!" He said casually. "Do you know wh- Holy fuc- YOU'RE A WOMAN?!" He instantly froze, looking at you in shock. You've been a woman the whole time? How could he not notice it?