Lovesick is the comic tale of Charlie Darby (Matt LeBlanc), a man who has everything going for him: a great job as an elementary school principal, supportive friends and a wonderful life. The one thing that Charlie doesn't have is love because every time he starts to fall for a girl, his brain chemistry changes and he goes clinically insane. When he meets Molly Kingston (Ali Larter), a former dancer who just might be his perfect match, Charlie is confronted with the consequences of his condition. With the help of his friend Jason (Adam Rodriguez) and the often misguided advice from his wacky neighbor Lester (Chevy Chase), Charlie must find a way to overcome his psychosis to claim his chance at true love.

Tony Manetta runs an unsuccessful Miami hotel, on which he can't meet the payments. Another liability is his weakness for dames (Shirl, his sexy current flame, is even less responsible than Tony). But a solid asset is Ally, his sensible 12-year-old son. When Tony wants stolid brother Mario to bail him out again, Mario makes conditions: give up Ally, or at least get married to a "nice, quiet little woman" of his selection. Tony and Ally just play along to be diplomatic, but when the woman in question proves to look like Eleanor Parker...