Fools Rush In (1997)

Sparks fly and cultures collide in this romantic comedy about a casual night of passion that turns into the love of a lifetime. Matthew Perry stars as Alex Whitman, a New Yorker sent to Las Vegas to oversee a construction project. There he meets Isabel Fuentes (Salma Hayek), and some serious chemistry brings them together for one night. But Alex doesn't see Isabel again until three months later, when he learns she is pregnant. On a whim and prayer, he proposes. However, there's more to marriage than a Vegas chapel and an Elvis impersonator, as Alex and Isabel soon learn. (imdb)