I am gonna throw a pool party for my friends but my cousins are gonna ruin it!!1 help me find a way please!!!?

i am gonna throw a pool party for me and like me and 8 friends. and my pool can hold up to like 8 people. and like all my friends that are gonna come are like 13-14. well so here is the problem, i have 3 cousins that my dad is forcing me to invite and they are 16 14 and 18. and my cousins are like SO annoying and they won't have any friends and my friends that are coming to my party don't really like them because they try to act all cool when they are really not.and i don't even like them ether and they always ruin everything so if they come to my party they will ruin it and then my guests wont have fun! ad my dad is saying they have to come! what can i do t fix this please!!! what do i do about them?!if i do invite them they will ruin my party and if i don't invite them my aunt will hit me and so will my dad and i would dishonor my family!! ugh what should i do?!!!!