She sleeps with pajamas, with puppy dogs and rainbows on them. And a long sleeve shirt.
Tony isn't stupid – about as far away as you can get from it, in fact, and he knew that entering a relationship with Pepper wouldn't be sexy lingerie every night.
But what he didn't expect was the fleece. The cutesy fleece pajama pants, with a matching long sleeve shirt that she slipped on for that first awkward (planned) sleep-over they had in their relationship.
Compared to the super-models and celebrates who had once entered and exited his bed, wearing a fraction of the clothing, the fuzzy clade form cuddling next to him was a change.
A change he began to appreciate, as purely Pepper.
Still, Tony thought flipping through the browser pages he had up on the computer in front of him, if she had to cover up all that tantalizing skin, at least until he could uncover it again, she could at least wear a pair with Iron Man on them.