"It's a shame 'cause you've been looking so great lately. So sexy!"
I have so much to say about this scene oh my god.
Starting with the fact Mac is just casually watching shirtless men workout on TV. But this scene is SUCH good proof that Dennis 100% knows what he's doing, aka nurturing Mac's dependence on him, aka literally using the SINNED system on Mac right before our eyes.
The use of the word "sexy" here is so interesting to me, because Dennis could've used so many other words to describe how he views Mac's physical form. He could've said Mac's been looking so strong, or ripped, or tough, or manly, but instead he lands on the word sexy. And he says it so deliberately!! He knows it's the best word to describe Mac. It's the most effective word he could use to convince Mac to go back to the cult, because if Mac is in the cult getting fit and not eating Thin Mints, then Dennis will think he's sexy. We can tell Dennis' verbiage works too because of the way Mac cocks his head. He's almost surprised at the descriptive use of the word "sexy." He straightens his posture. "Oh, Dennis thought I was sexy?"
Mac is visibly upset at the notion that Dennis is disappointed in him. This is such an obvious use of Dennis praising and then withholding praise from Mac. Dennis is fully aware that in giving the dog a bone, Mac will do whatever it takes to earn the more significant prize. Dennis allows Mac a fragment of his praise because he knows in doing so Mac will believe it's possible to earn more. Mac knows what it feels like to earn Dennis' affections and now he wants nothing more than to have that back. If Mac can please Dennis just enough, he might be praised by Dennis again.
The absurdity comes in later seasons when Mac follows Dennis at his heels like a lost puppy, desperate for Dennis' love and affection, and Dennis acts as if he didn't purposefully and meticulously train this man to act this way. Dennis Reynolds truly is a bastard man.