Be the butt of something
Definition 1 of 1
Pro Tip 1/3Negative Connotation
This phrase implies negativity and should be used with sensitivity to not hurt feelings. 
She didn’t enjoy constantly being the butt of his sarcasm.
Pro Tip 2/3Informal Context
Use it in informal situations, as it's casual and might be inappropriate in formal contexts. 
At family gatherings, I always seem to be the butt of playful teasing.
Pro Tip 3/3Group Dynamics
Frequently used to describe dynamics within a group where one member is teased more often. 
New interns are usually the butt of jokes at the office.