Used to describe something or someone that is very gay.
Look at Justin's shirt. That thing is gayer than a bag full of rainbow colored rubber dicks.
An insult used against a very fat and jiggly person.
“Shut up you bin bag full of porridge”
Aggressively homosexual
“That man is gayer than a bag full of butterflies.” - Sean Davies
Another saying for definitely or 100 percent.
To confirm something has happened or will happen. It comes from the nursery rhyme about the farmer getting 3 bags full of wool.
"Do you think you've done good on that test"
"Yeah mate, 3 bags full"