You knock his hands away. "Whoa there, buddy. I can undress myself."
He backs up, seemingly to laugh at you silently with his eyes and lolling tongue. "Well then?" he presses. "Is that a yes?"
"Hmm..." When you'd thought "vixen" in the past, you hadn't imagined it quite this literally. Still, that anthro form isn't bad at all, and there's a strange exotic beauty to the head and tail that adds to, rather than detracts from, the seductiveness of his body. Now just imagine it with hips and boobs... and a wet, needy snatch in place of that ballsack...
"If that's want you really want..." You gaze up at the voluptuous vulpine in the painting, then back to the fox. "If you're so desperate for a mate that you're willing to be a vixen, then I won't stop you."
Mind made up, you quickly shuck off your clothes and shoes, and stand naked before the fox. You ignore his smirk as you stroke your cock to hardness.
"So, how do we do this?"
Given that he's a little taller than you, and the angle of his sheath, it's a little difficult, but with his help and using the wall as a brace, you manage to slide it in. And once in place, you begin to thrust enthusiastically, eager to claim your promised vixen.
The fox man, for his part, seems just as eager. You aren't exactly pleased when you realise the position he has you in -- back to the wall, as though YOU were the submissive one. And while his fur feels nice against your bare skin, you're not sure you like the way he's running his hands over you like he owns you.
"This'll be fun," he chuckles, and you feel him thrusting back, his pointed tip pressing into your more rounded head inside his sheath.
"Yeah." Though suddenly you're not sure of his intentions. But -- shoot, what are you worried about? He asked you to fuck away his manhood, and that's what you're going to do!