It refers to the strongest bond that could be formed between two people i.e when two people connect with their souls. It is the rarest form of friendship.
Always their for you no matter what, cant be away from eachother for more then a day , laughs all the time, has great times to togethr, always telling sercrets, beingg their for them through thick and thin , loving to eachother, Enjoys just talking
Erin - I Bout lost it when you peed your pants from us laughing to much!