If the beast was dangerous enough, I think the beast would kill the man or woman who decided to lie with it long before any other humans got a chance to.
ZOOPHILES; And if a woman approach unto any beast, and lie down thereto, thou shalt kill the woman, and the beast: they shall surely be put to death; their blood shall be upon them.
Leviticus 20:16; And if a man lie with a beast, he shall surely be put to death: and ye shall slay the beast.
Leviticus 20:15