I was fully prepared to enjoy this sex comedy and musical about young couples in Madrid playing musical beds, even if the songs were second-rate and the performances a little slapdashin this context, feeling and vulnerability often count for more than professionalism. But despite a brisk opening and some agreeable (if sloppy) choreography at the very end, I was less than tickled by the premise of David Serrano’s scriptthat the characters lie to and betray one another as naturally as they breathe. This reportedly did well in Spain, but I don’t know whether to credit the cast (Erneso Alterio, Paz Vega, Guillermo Toledo, Nathalia Verbeke) or the audience’s cynicism. Emilio Martinez-Lazaro directed; in Spanish with subtitles. 114 min. (JR)