I'm grossed out that my sister licks the ice cream lid
Why do you find that gross?
I think that's disgusting. She always licks the top of the ice cream carton, and she forces me to do it, too.
That sounds normal to me. Plus, I highly doubt she can force you to lick an ice cream lid.
She's my little sister. She's always been annoying.
Most people find their siblings annoying. It's a perfectly normal feeling to have.