"Did you just double-dip that chip?"
"You double-dipped the chip."
"Double-dipped? What are you talking about?"
"You dipped the chip, you took a bite, and you dipped again."
"That's like putting your whole mouth right in the dip. Look, from now on when you take a chip, just take one dip and end it."
Billy: ice cream?
Jared: nah! I nailed my ex and then went to my booty calls house right after and nailed her to.. Double dipped it
In particular, refers to acid that has been 'double dipped', however can also be used to describe a range of potent substances/activities/ people etc
See also fat old boy.