Haven't had tea dances or inter-school dances (boys school socialises with girls school with teachers looking on disapprovingly - very much a cattle market) since the 1970s.

But given that the Wizarding World is 50 years behind the times I suppose you can get away with all those marriage law fics.

Brits Do Not Date.

Given the period I suspect that James' eventual proposition to Lily was along the lines of "Get your coat, luv. You've pulled."