I must say that this not a boring film at all, although I found the endless little quarrels a bit tiresome. It is hard, though, for a non-French person to judge just how much of all this is meant to portray the character of "the French" (if anything like that exists) and how much is mere parody exploiting and playing with the cliché that French people always think about love and sex. For example, is Marion's father supposed to be a prototype or simply a caricature? Knowing this would be of great help in evaluating this movie.
On the other hand, the film is very balanced in its attempt to weigh Marion's delight in experiment against Jack's conservative rationalism with regard to relationships. In other respects, of course, Jack is not rational at all, for example concerning his hypochondria. Whether one wants to call him touchy and easily offended will probably also depend on whether you think that, in the first place, he is being treated badly by all those slightly crazy Parisians or whether you would rather want to say that he is a bit stiff and inhibited.
In any case, this is a nice little film about the difficult task to lead a cross-national relationship and about the fact that thinking you know your partner is not the same as knowing her or his culture.
But don't expect to see a romance like in "Before Sunrise"!!