They’ve never been “brothers”. It’s frustrating that it’s the most common description of their relationship, so what would you truly label them?

The closest that we can get to this is to refer to them as “quasi stepbrothers”, but even that’s a stretch. We know that their moms were not only never legally married at all, but they weren’t really together for too long either.

I realize it’s just a convenient title, but what do you opine?