Book a weekend for two in Barcelona. It's a city which can be whatever you want . (A beach resort, a place with romantic restaurants, a city with lively nightlife, a heaven for shopaholics or a Mecca for culture vultures).
There are loads of cheap flights to Barcelona from all over the UK, either directly into Barcelona (El Prat) airport (with easyJet, Ryanair, BA, Monarch and Jet2) or linked by an hour's bus ride from Reus or Girona (with Ryanair).
http://www.barcelonaturisme.com/English/