When David journeys to Australia to marry the love of his life, Mia, he invites his three best mates - Graham, Luke and Tom - to travel with him. Having barely met his bride-to-be, they aren't too impressed at the thought of losing their best friend to married life on the other side of the world but resolve to give him a send-off to remember.

After a final carnage-filled stag night the big day arrives and the trio of ill-prepared best men end up giving a whole new meaning to the phrase 'for better or worse' as a chaos-filled wedding, complete with a deranged drug dealer, a cross-dressed sheep, a coked-up mother-in-law and possibly the most disastrous speech of all time, threaten to derail the marriage before it's even begun.