By their joined hands, he could feel her blood pumping too quickly through her, and knew it was his doing. He wanted to tell her five different things at once, and he wanted to ask her ten. His mind swiftly sorted out the most important, most crucial thing -- and he said it.
"Selina Kyle, I am hopelessly in love with you."
And it wasn't the same as asking her the first question on his mind, and it didn't set his mind at ease at all - but this was the thing he needed her to know immediately. If her pulse kept racing and her eyes didn't fill back up with the light he loved about her, then he would have a few answers -- not the ones he wanted, but a few all the same. And if he returned some of her vitality, then other questions were answered, too.