A dinner party hosted by his sister Elizabeth and her husband Peter gives Vincent the perfect platform to cause controversy with the revelation of what he plans to name his unborn child.
But it leads to far more uncomfortable discussions that unleash long-held resentments, secrets and unspoken truths.
Written by Matthieu Delaporte and Alexandre De La Patelliere, the fascinating play has been adapted and translated well by Jeremy Sams, who also directs, to maintain the sharp wit and momentum of the comedy.
While at the beginning, there are some German-related comments about cars that don't fit in culturally with British attitudes, on the whole, the adaptation fits well with a group of extended friends and siblings in middle-class London.
Where it excels is that it's a very human drama with much of the astute comedy coming from moments of frustration that any couple or sibling will recognise from their own life.
It bubbles along nicely with constant laughs along the way at speed with fast dialogue and quips.
Thomas is a confident lead, once again showing his natural aptitude for comedy with some slight similarities to his role of Simon in The Inbetweeners.
There is a strong cast around him in this slick production, who all gel well together. Bo Poraj - better known as Mike in BBC comedy Miranda - gives character Peter a constant sense of annoyance and is the more serious, deadpan role opposite mischievous Vincent.
Emma Carter as harangued sister, wife and mother Elizabeth is a key central piece in the play and makes the audience have sympathy with the character's frustrations, getting the ultimate showdown of the performance.