Anyone who’s seen him as sagacious smack dealer Stinger Bell in HBO’s The Wire knows Idris Elba’s movie career will soon be off to a promising start. Sadly This Christmas isn’t it. Elba plays one of the six children of large-bosomed matriarch Ma’Dere (Loretta Devine), who've gathered together to celebrate the festive season. There's lame gags a-plenty, mushy bonding scenes and the revelation of a few deeply predictable secrets. In particular, the inter-racial marriage plotline is either hopelessly out of date, or - God help 'em - revealing of the very sorry state of U.S. race relations. This might pass for entertainment on Boxing Day, after four sherries and a box of liquor chocolates, but it’s still the kind of 14-pound turkey you can only excuse at Christmas.