If you were to look at Baelish's actions -- like arriving with the Knights of the Vale to help Jon Snow win the otherwise surely lost the Battle of the Bastards -- it's also possible to view him as a pragmatist. Like Varys, he's put his considerable mental energy behind supporting a brave, noble leader. He's providing counsel and mentorship to Snow's half-sister Sansa Stark. He's even brought some military might to the table. What a good guy, right?
Not exactly. Baelish's loyalty to the Starks is borne out of his creepy obsession with Catelyn Stark, which he has now channelled into an even creepier obsession with her daughter, Sansa. He doesn't have a secret bleeding heart like Varys; instead, he only has more layers of personal ambition. That's always been bubbling beneath the surface in any Littlefinger scene -- Gillen remains a master of furrowing his brow in a squirm-inducing way -- but last night he brought his lusty intentions to the surface by basically telling Jon, in a leaky crypt no less, he wanted to have sex with his sister. Not a smart move. Snow reacted the way you'd expect: grabbing Littlefinger by the throat and seething, "Touch my sister and I'll kill you myself."