The thing is, it's not a good look. The game has already copped ridicule across the board. Sure I know it's often hypocricy with other footy codes having their own skeletons in the closet... but imo, we can do better.
The SMH have already made sport of it.
And as for Stevens thinking it's not against the rules, I would suggest it can easily be against the rules if the NRL decided he was bringing the game into disrepute. Also, I'm pretty sure that putting hands between the legs is against the rules in some manner. And there's there deliberately slowing down the play-the-ball.
If I was the ref, I'd warn him before kickoff not to try it on, or he'd spend 10 minutes in the bin.
And then ofcourse there's the issue that he simply shouldn't even be asking if it's against the rules.