I did not masturbate and I have large labia and since I became
sexually active/started masturbating, the size of my labia hasn't
changed.
getting your labia bigger from masturbation and sex is
the joke teenage kids like to make.
Many small-lipped women
have masturbated much more than you and you can just look at the
small labia of porn stars to believe it.
The real cause of
big labia is genetics, hormonal changes, some pills (not sure which
ones).
Unless you practice some extreme deliberate stretching,
hanging weight from your labia, hanging yourself from the ceiling by
your labia (what?), it's unlikely to get your labia permanently
stretched.