The movie based on an up coming Seattle wedding, is centered around the would be bridegroom Paul played by Jason Lee.

Paul is an advertising salesman who wakes up the morning after his bachelor party, in bed with hula dancer Becky (Julia Stiles). Becky flees, leaving behind her underwear which Paul tries to hide from his fiancée Karen (Selma Blair). Paul cannot remember exactly what happened that night. Even though it was an innocent encounter, Paul thinks that something had happened between Becky and him. To cover up, Paul starts lying and things get worse when Becky turns out to be Karen's cousin. They meet again and again and starts falling for each other. He realises that the fun loving Becky is more to his liking than the perfect, sweet Karen.

The movie has a fairly good cast and a few funny moments but talents are totally wasted. Lee had done a great job in the film 'Almost Famous' as a supporting actor, but he doesn't reach up to the mark in this film. His confused character in the film just stumbles along with the happenings doing nothing much. Selma Blair looks good and Julia Stiles is good in what ever she has to do which isn't much. Thomas Lennon reserved character as Paul's brother Peter, is notable.

The movie takes the title ' A Guy Thing' from a joke in the film which refers to a women's underwear in the toilet tank, which is far from comical. As in "Just Married", this movie also deals with a generation Y, which is marriage minded but don't have a clue how to make it work and do the things just for the sake of doing it. Apart from a few laughs the film has nothing much to offer.

We rate this movie Below Average.