An incredulously large pair of breasts found on a slim girl.
Eye poppingly large boobies which are bursting out of their bra and yearning to be set free. They're bra-bursting, sumptuous and presumptuous!!! They assume the world needs to see them and they're right!
"Crikey Bruce, look at the brasumptious chesticles on that Sheila"
"Did you see the bird Craig got off with?"
"Yeah mate, she had a right pair of brasumptious chesticles!"
"Did you see Brett bump into that girl at the bar?"
"Yeah, he got a faceful of brasumptious chesticles. Lucky bastard"