What does it mean to be manly?

ok so my gf knows im sweet and nice and we can talk about anything but she tould me ohh i really wanna see your manly side idk what she means by that. i tould her i played basketball (im in varsity) and i tould her i dont like to get sweaty cause its gross and she said y not i like it its very manly? so i know she likes manly but i dont know what she means by it? anyone wanna help