Look at my ass

Means you are annoying/You hated me and now my ass is bigger than yours and I have glowed up(sentence NOT meant to insult any Sallies I needed a name for example)

"Look at my ass Sally, you don't deserve my friendship or companionship

Don't be looking at my ass

When a divorced rough middle aged man catches you looking at his ass whilst he holds an item of choice

Guy: Wow look at his ass
Divorced man: Don't be looking at my ass (item of choice is a cold coffee)