Boomerfuel comes from the common ok boomer phrase used to demean people of the baby boomergeneration. Boomerfuel is a message, meme, or any other form of media that supports and reinforces a boomer's belifs in one way or another, 'fuelling' a boomer's belifs.
When a bunch of dudes are together at a strip club or a party when they want ass but no chicks. A bunch of guys that get boners together but not because of each other but because of the lack of pussy and the need to hit it.