So I apologize if there'a already a thread on this, but if so, I could not find it.
So basically, there's so far no indication of who Metal's mother is, but we know who his father is, Rock Lee.
Now, I've been looking through the possibilities and I found there is only one that I find Plausible, Tenten. Tenten and Lee have never shown any affection towards each other with the exception of both being members of team Guy. Neither are they married like everyone else seem to be.
So my thought is that either, Metal was born out of wedlock -OR- Lee is divorced.
PS: This isn't supposed to be some sort of Shipping discussion. I am merely looking for plausible theories in the attempt to deduce Metal's mother. I don't believe Kishimoto would have overlooked something like this.