He's calculating and suspicious nearly the entire time Alastor monologued with his intentions. Vox balks slightly as his sides are patted feeling a combination of embarrassment and indignation at the implication. So he'd been mostly sedentary and relying predominantly on processed junk food for a cheap boost of serotonin in dire times, that didn't mean he was anything less than the lean, mean, sharp machine he was in previous eras!
"Are you calling me fat??" He couldn't help but trip into the very provocation Alastor had knowingly set up for him.
Okay, so maybe he'd let himself go a bit this past month, but it wasn't anything significant!
And... yeah, it was true, he'd not exactly demonstrated shyness before... Not after rolling Alastor's chair into his bedroom and in a mostly literal sense, swung his dick around to express dominance (since neither Al nor Val had been overly impressed with the figurative performance). He felt an tsunami's wave of regret and retrospective shame for his actions now that he was nothing more than a great, big, fat, loser, in Alastor's eyes. Who also apparently couldn't dress well.
"Wait you mean you want me to change right here?" This implication also sparked a hint of panic on Vox's part as he looked around the boutique in desperate search of a fitting room and coming up short. No employees, no curtain to hide behind, just Alastor and his knowing look.
The only way to conceivably level the playing field was to take Alastor up on his offer. And Vox was so preoccupied with finding the perfect article of clothing to solve his predicament he forgot to feel any level of excitement by the prospects of what Alastor had just offered him. In another context he would have certainly realized how rare the opportunity that had just been thrust upon him actually was.
"Fuck, I don't know?" he scanned the store for something to wear. Then his eyes skittered to the shirt. It was rather simple but... Something that had grown oddly popular in his own era on Earth. One of those striped button up bowling shirts, with a frocket on the front. Oh, actually he really wanted to see Al in one of these. It was on just the right side of tacky (at least in Vox's opinion) and just whimsical enough to possibly get the greenlight on Alastor's side of things. Besides there was a whole hipster fashion counter-culture to back it up as a reasonable option to wear outside the bowling context.
"Hey look, this one's even in your colors," he took it off the rack trying to seem casual about it. "Red and black."
Now it was his turn to hold it up near Alastor's body, not actually touching him at any point, but squinting in feigned analytics.