What's an underrated navel / stomach reveal accident you like that females do which doesn't get discussed enough ? (Example...)

For example, I've seen rare moments in real life from where girls / women adjust their outfits by pulling their jeans up to their waist and do that small jumping motion while they quickly lift their shirt up for a second and then pull it back down giving me a flash of their stomach and bellybutton (That's happened with acquaintances to).