Quote #2
So uppon a day Sir Trystrames talked with La Beale Isode in a wyndowe, and that aspyed Sir Andred and tolde the kyng. Than Kyng Marke toke a swerde in his honde and cam to Sir Trystrames and called hym “false traytowre,” and wolde have stryken hym. (266.19-22)

There’s actually a double-dose of betrayal going on here. The one that probably first comes to mind is the affair between Trystram and Isode, which is a betrayal of King Mark. And the other? Andred’s exposure of Trystram, his own cousin.