That this comes from Guy Jenkin and Andy Hamilton, writers
of Outnumbered, should give you an immediate idea of tone. This is a cute, gently arch comedy about a splintering couple (Rosamund Pike and David Tennant) taking their three children
to their grandad’s (Billy Connolly) birthday party and trying not to let on that they’re divorcing. Mostly it’s hugely likable, with particularly good scenes between the kids and Connolly, but there is a pivotal event that is just too dark to be giggled off. It finds its way back for the ending, but in the middle there, it gets weird.