Losin' It (1982) on Netflix

Plot summary

Dave Cartman, Spider Church and Woody are high school seniors in Southern California who plan a trip to Tijuana, where the three of them intend to lose their virginity. When Perlman, the fourth member of the group, backs out, he leaves them short of the money they need. Dave's younger brother Wendell, called Wimp, offers to cover the difference if he can come along, and Dave agrees, hoping the boy will stay out of the way. Spider is held after school for a fight and slips away to join the others. On the road the friends stop at a grocery store, where the owners, Larry and Kathy, are arguing, and the boys take supplies without paying. Kathy asks for a ride, saying she wants a Mexican divorce. In Tijuana, Dave orders new seats for his Chevrolet.