Despite how Wanda managed to reassure herself, there was the briefest flicker of mistrust from Tony that he either was confident didn't show, or he didn't care to bother to hide it. He had seen Sinister take other shapes, and knew well enough his ability to manipulate another's mind. He couldn't fault Wanda for falling for the kind of tricks that creature could conjure; after all, everyone else had fallen to the belief that it wasn't one he would try again. But this was enough proof that they had to be vigilant, and trust was going to be hard-won.
In that flicker, he had to reassure himself that this was Wanda. Then he leaned forward with a hand against her back and held a kiss against her chest, knowing that perfume and that tension up her back and that unsure breath better than Wanda did. He had watched her enough.