Put it at the end of a short exchange, after the question has been shown on screen, then follow it with a bruh for a second beat, or an emotional damage sting to close a roast reply. Keep it as the final line so the exchange ends on the dismissal.
About this sound
This is a very short spoken clip, lasting about a second and a half, in which a flat voice delivers the line "go and ask your grandfather." The delivery feels dry and lightly mocking, turning an oddly old-fashioned generational jab into a quick comeback. It lands as funny and slightly awkward, sharper than a generic insult because the specific wording makes the dismissal feel deliberate and memorable.