im preety sure I just saw my brother having gay sex

today me (16M) wanted to ask my brother(also 16M) if he wanted to eat pizza i ordered, i went to ask and heard moans coming from the room because the door was slightly opened, i looked inside and he was on top of his friend(17M) in a skirt and thigh high socks, now i think he thought he was gonna be home alone for longer since i went out at 3 pm and was supposed to be back at 9 but i came back at 7, i have no idea what to do now since i now know that my brother is gay and he had sex with his friend on his bed☠️