He slammed the door because her face was surprised, rather than aroused, or welcoming, or smiling, or grateful, or or or —

Not that anyone can plan for “how to react when surprised by something you can’t process in time” — it’s not her fault. But just the fact that her reaction wasn’t what he wished for, wanted, didn’t know he wanted…

I doubt it was his first time, doubt he felt any shame in the wearing, just the freak-out of her surprise arrival followed by the missing reaction from her that might’ve made it all right…
There’s a look, a heavy-lidded desire that comes to the face,
a flush of arousal and
an involuntary response that occurs before thinking starts,
before even surprise begins…
If he’d seen/felt/sensed that the sight of him was as good for her as the sensation of the smooth constriction of panties was for him, well, that’s another story… one closer to your own amusing and familiar tale of tail… Good for you, too bad for her —

But it’s none of my business. Not here, at least…

You are such a writer, Sugar.

Keep on.