Don Draper

Don Draper, played by Jon Hamm, is not 'Dad of the Year' material in 'Favors.' (Michael Yarish/AMC / March 20, 2013)

Bob Benson’s secret is finally revealed. And, no, it’s not teaming with the NSA to spy on SC&P’s phone conversations.

But before we get into that, let’s talk about Don helping someone else run from the military for a change.

This season has been somewhat slow and slightly spotty, especially when delving into current affairs (see: the MLK assassination, which featured next-to-no perspective from the black characters).

At times, this season has briefly alluded to the Vietnam War, whether it’s Kevin’s Greg's self-imposed stay in the Army or Ginsberg lamenting the war’s 200 body bags a week. But it wasn’t until this episode that Don gets entangled in draft dodging.

When Mitchell asks Megan for advice on fleeing to Canada to dodge the draft, Don’s convinced Mitch should man up and head to war: “He can’t spend the rest of his life on the run.” Only Don Draper can pull that off.

When Don and Dr. Rosen head to a bar, however, he changes his tune. He lauds Mitchell for his idealism, playing devil’s advocate to Arnie’s service-and-sacrifice stance.

But more importantly, Don’s bar chat with Arnie was riddled with hints that someone was going to find out about his affair with Sylvia. We just didn’t know it would be Sally.

“I’ve been meaning to knock on your door anyway… for Mets tickets.” Even more telling is when Arnie reveals she says she’s been lying about little things.

But Don doesn’t care about these scares; he’s got a woman to win back. With a compromise of his morals -- and a couple of uncomfortable conversations -- he finds a way to help the long-haired Mitchell avoid combat.

But of course, it’s not just for Mitchell. He calls Sylvia to tell her the good news. Relieved and grateful, she also asks why.

“I have children, too,” he tells her. “I know that’s not why you’re doing it,” she says, seeing right through him.

She then gives Don a bizarre reason for ending their affair. “I hope you know I was just frustrated with you.” Is frustration a sign of PTSD? Because that’s not quite the emotion I was expecting from a woman who was kept as a sex slave in a hotel room for a few days.

Then she gives the most ass-backwards confession ever: “You were good to me. Better than I was to you.” Uh, is she on some sort of weed/LSD/speed/hash mix? Because she’s more delusional than Ginsy. (Poor kid. Wonder what he was up to this episode?)

And just like all the other favors he’s done for her (cough, money), she repays him with a lunchtime quickie, interrupted by Sally.

Arnold, unaware of Don’s selfish motives, visits the Drapers during dinner and praises him for his heroism.

“You are the sweetest man!” Megan coos, kissing him.

“You make me sick!” Sally shouts, running to her room.

Don chases after her and gives her a the lamest excuse: “I was comforting Mrs. Rosen.” That might as well be the “dog ate my homework” excuse for philanderers.

Wiping away her tears, she mumbles, “OK.”

There’s nothing else she really can say. Walking in on your parents is traumatizing, but finding out your dad is having an affair, even if it’s not your mother he’s cheating on, is heartbreaking.