Going to the Nail Salon? Cuticles?

okay...so im about to go get my nails done with my cousins and hardly ever get my nails done! im 13 and have probably only gone like 5 times ever. and whenever ive gone my sis has been with me and she tells the lady not to cut my cuticle, but shes not going with me now.... so what exactly happens when you cut your cuticle. Does it hurt? should i tell the lady not to or just keep my mouth shut? I know that it can cause infection and stuff but i really have no idea what its like! ive gotten it pushed back before but never cut!! Help please!