Paul is feeling romantic toward his wife. she is most likely to detect his interest in her by changes in the appearance of his eyes caused by

I believe the answer is: dilation of the pupils

Our pupils would automatically dilated whenever we feel a certain level of excitement. During interaction between two different people, this excitement could be interpreted as sexual attraction. This is why Paul's wife could detect paul's interest. (especially if they are currently conducting a physical contact)

what he said above me         look up that's the answer