I pee my pants at night! And there's a slumber paty!?

Only my friends mom knows! I have to wear extra thick diapers at night that really show threw my pajamas! I know to put them on after everyone goes to bed, but i fall asleep easily so i have to put them on before! Especially cause we watch tons of movies. Anyway at sleepovers thay usually prank the first girl or girls who fall asleep which i'm scared will be me!! they usually take there clothes and hide them then take off there pj bottoms!!! and hide those!! this is my first slumber party with this many girls, i think 9 are going! should i tell them, but im scared they'll make fun of me and take my pj pants and other pants so i have to wear a diaper!! am i overreacting!!?? what should i do? and i don't want to not go cause im really excited!!