The Doctor quite liked kissing, and he was getting pretty good at it if he did say so himself. He knew that Rose had been unsettled by the presence of her younger self, and while part of his sympathized, another part wished she could more easily accept the younger Rose's presence. He loved them both. There was no getting around that. They were both Rose. They were the same person even moreso than he was the same person as his fully Time Lord counterparts.
"Course I'll miss this," he told her when she asked. "Still. I quite like the idea of a domestic adventure as long as it's with you. Plus, we have that bit of TARDIS to grow. She'll be ready in a few years if we decide we want to start traveling again, and in the meantime, we've got the whole of Pete's World to explore, haven't we? Besides. We'll need a bit of time for the children to grow, as well. They'll need to get some practice at running before we take them anywhere."