As is so often the case with Rebecca, the expression on her face tells much of the story. In this case, it was one of, well, horror may be too strong a word, but is in the right vicinity. She certainly didn't find what she expected, and what she found was ... well, more than enough for her stop the seduction.
My first thought was that maybe Burton is a woman, but that doesn't seem quite right, either. What happened to him in prison - in another strong scene in which Proctor discovers him - is likely the source of the answer. And, not to be too graphic about it, but likely something was badly maimed, or worse. Leave it to Banshee to bring us down this path, as we struggle to learn the origin of this charismatic character.
Meanwhile, in New Orleans, Chayton put up a better than good fight, but the inexorable logic of the narrative - meaning, Hood couldn't die - not to mention moral justice, demanded that Chayton be the one who was ended. The coda, of his body with the fish, provides a good couplet with his rising out of the water the last time we thought he might be dead.
So a major bad guy is gone. But the heist last week has set a new enemy against Hood and his friends. And this one combines not only considerable strength and savvy - as did Chayton - but a team who can help him figure out what happened, i.e., how he managed to be robbed.
As we see in the diner, he's well on the way to figuring this out, and acting upon it. Should be a strong two concluding episodes of this season, as Hood struggles to stay on top and ahead of this.
See also Banshee 3.1: Taking Stock ... Banshee 3.2: Women in Charge ...Banshee 3.3: Burton vs. Nola ... Banshee 3.4: Burton and Rebecca ... Banshee 3.5: Almost the Alamo ... Banshee 3.6: Perfect What-If Bookends ... Banshee 3.7: Movie with Movie