Comic relief character in Fear

When 16-year-old Nicole Walker meets 23-year-old David McCall at a Seattle nightclub, she falls in love. David is exciting and charming, and despite the wide age gap, he wins over Nicole's family -- except for her workaholic father, Steven and her goofy wisecracking brother Jay, their suspicious of David from the start. Their concerns are realized when David turns out to be a violent sociopath who sees Nicole as his possession, and her family home a fortress to be invaded.

PS I do not own the movie Fear