Robb has not actually gone on many dates, before. His romantic experience went something like:

Betrothed but not to anybody in particular.
Married more or less by accident.
Had a lover, but hadn't realised it in time to date first.
Married again, to same woman as before.
Single father.

He had actually taken Jeyne on date-like things, at the beginning when she'd arrived and they were getting to know each other again. His creativity is not boundless, however, and he feels that re-using an idea he'd previously used with his wife would be dishonourable somehow, and also that Jeyne and Delirium were actually unlikely to enjoy quite the same things.

Still, there are only so many things to do, on the island. He'd finally decided to stop worrying about it. It's more likely to surprise her if it's a sort of surprise for him, too.

She's waiting for him, looking a bit like part of the landscape in a way he can't entirely explain. "Hello, Del. That's a lovely dress."