Hot boots / shoe -not sure what's needed?

My boy said he'd like to see me in "fm boots" or "fm shoes". I don't know what the fm bit means and I didn't want to appear stupid so I just said, "ah ok, I might look into it", thinking he maybe meant dm boots (doc martens) but I haven't a clue. Does anyone know what these are or why he'd want me to wear them, or what to wear them with? Links would be good.