its another word for "bestie bae" except instead of the word bestie you replace it with breast so then it turns into "breastie bae" it can be used casually in coversation in place of bestie
Jim:"So, Carol, are you going out to dinner with the guys and me tonight?
Carol:"No, sorry Jim"
Jim:"I thought that you said earlier that you could go"
Carol:"Brittany and I are watching Netflix tonight, breasties before testes!
A colloquial term, used primarily in mens lockerrooms, for the female breasts, of the larger variety. Thought to be a cunning linquistic derivative of 'vestibules'
Did you see that woman who just walked by?....of a set of breastibules. I would love to see her naked.