DH and I are visiting DS for lunch/early dinner on the last Saturday of May as it's his birthday, he's at Cambridge Uni in the middle of exams, so we're just going to take him and his girlfriend for a nice celebratory lunch/early dinner and then leave. I'd be grateful for recommendations, somewhere special that they wouldn't normally go to as students, but not OTT. They're not going to have anything remotely elegant to wear and personally I can no longer be bothered to dress up, so somewhere special but without being posh would be nice. Thanks!