J/R states:
A runner must prove by his actions and the way he positions himself that his intent
is to reach and stay on a base safely. Actions that disregard this intent and show,
rather, an intent to interfere include:
(a) grabbing, tackling, or assaulting a fielder.
(b) intentionally standing and blocking a fielder.
(c) waving arms.
(d) slapping a fielder's glove or mitt.
(e) going beyond (over-running) second or third base in a try to hinder a
fielder.
(f) sliding more than a body's length from a base in a try to hinder a fielder.
Common sense would also tell you this is not in the spirit and intent of the game. I would likely warn the runner to discontinue. Any further such action, which I suspect would be unlikely, would be cause for perhaps calling him out (interference per J/R) or ejection for unsportsmanlike conduct. I think it would fall into a 9.01(c) category in the rulebook for you to handle as you best see fit.
Just my opinion,
Freix