invited... but to pay

Has anyone ever been invited to eat & automatically assume that they are not paying for the meal?  Lets just say, like for instance if it were your boss who invited you.

Talk about frustrating.
Especially when you don't have the xtra money to be footing the bill for a lunchtime outing in the first place.

Lets say you had other "plans" for your paycheck that week.  Like maybe bills or something kinda important.

And the fuse gets shorter.