two female friends that have attractive breasts, and are comfortable enough to take a bath with each other, change in front of each other, and when photographed, usually will pose close enough for their breasts to smush against each other. ( derived from besties
Joe: You know Megan and April have been getting close to each other, lately.
Mac: Yeah I know, have you seen Megan's profile pic?
Joe: The one with both of them in it?
Mac: Uh-hun, they are such breasties.