An appalling situation. A bridegroom wakes on his wedding morning in his own bridal suite, with his bride-to-be about to arrive any moment, and finds a strange girl in bed beside him. What's more an extremely attractive girl whom, in the depths of his post stag-night hangover, he can't remotely remember even having been introduced to. Worse - during the ensuing panic to get the stranger dressed and out of the way, the bride arrives and the girl is trapped in the bathroom. The only way out of the dilemma is to persuade the best man to pretend that the hidden girl is his girl friend. Then the problem is that the best man’s real girl friend has to be kept ignorant of the fact. By the time the bride's parents and half the hotel staff get in on the act, the chaos reaches nuclear proportions!