A relationship broakup (or otherwise simply known as a broakup) refers to the ending of a relationship, typically a bromantic one (see: Bromance). A broakup can vary from casual to emotionally traumatic. The cause itself can be related to a degradation of the relationship between bros (rolling back to "friends", or worse, to "acquaintances") or in the most tragic cases, to circumstances bigger than said individuals (i.e marriage, graduation, moving, etc.).
In case of a very abrupt and definitive separation, or when the broakup ends a very profound and intense bromance, the term "brovorce" may be more appropriate (see: Brovorce).
Jim: "Tomorrow Tom will move from our apartment. We shared it for 8 years, and tonight will be the last time we go out to party until there's not a single bar open and come home to drink the last shot before passing out. I feel like shit."
Andrew: "Cheer up, broakups can be bad, but i'm sure you two will still manage to do that every now and then, even if he's going to live 100 miles from you."