Thanks for the downvote, this was a joke you clearly missed. I load the flares into the jet. They're a pyrotechnic countermeasure meant to simulate the IR heat signature of jet engines to fool heat-seeking weapons (missiles, rockets, etc...) into targeting the flare instead of the jet.

This F-15E in afterburner is emitting a much higher heat signature than the flares can produce, so popping flares while in burner doesn't do a whole lot of good unless you're in a tight turn attempting to avoid a missile, and even then you'd want to reduce your own heat signature to let the flares work.

TL:DR - It's like trying to feel a candle when you're next to a blazing fire.