A small, petty part of Andrew wants her to regret it as much as she possibly can. He's never hidden how jealous of the Doctor he is, except perhaps by dint of disguising it as determination to go on being the Doctor.

On the other hand, the better -- and larger -- part of him hates to see her hurting. He knows what she's said is true, and that no amount of arguing will change it. He's bright enough to realize, too, that by arguing with her, he endangers what affection she does hold for him. With a sigh, he reaches out to take her into a hug, wanting to hold her tight even if he knows he won't get to keep her.