It was safe to say that with Midas' sophistry and his capability of saying things without saying them, and the other two's silence that Schadenfreude fueled, Jax was soon able to find himself imagining all sorts of scenarios for how his unconscious sexual assault happened.
Jax even started thinking there were fingers in butts and the more he tried to confirm this with Midas saying it was better for him to not try and find out, the more Jax became convinced that Midas was trying to protect him.
If Midas was protecting him, then it must be true was what he thought, and this made his resentment for the beast increase greatly, even fuelling some less than friendly suggestions from Jax to Midas on how the beast was supposed to be dealt with when they got back.
Why don't we kill it publicly in the most morbid of fashions? Why don't we dismember its limbs and leave it with four stumps, and then have everyone beat it up until it dies?