How to avoid somebody you see everyday?

So these guests are staying at my house and they are the epitome of rude and annoying. We're having a family picnic tomorrow. During these picnics, I usually wander about and hang out with my favorite. My older sister told me that I could hang out with her, my cousin, and her favorite cousin so we could avoid the guests. I agreed, since it sounds fun and relaxing, and it'd be easy to avoid them with some help. I just know, I just have that feeling in my gut, that the guests will follow us around. Here's an example: Last year me and my cousin used large wooden sticks to knock berries out of trees. We used two cups to wash the berries and strain the water out. This year's estimation: The guests will drag the sticks across the ground to spell out something very stupid, then they will spill the berry water and eat all the berries. PLEASE HELP!