My Teacher's Wife (1999) on Netflix

Plot summary

Todd Boomer is a senior at Southport High School, and his lifelong dream is a place at Harvard. What stands in his way is calculus: his teacher, Roy Mueller, is hard-nosed and unpleasant, and he fails Todd on test after test, so his grades are not good enough for the university he wants. Todd, an aspiring cartoonist, enlists the tutoring help of Vicki, a gorgeous and mysterious mathematical genius who agrees to work with him and to bring his grades up. The lessons carry on past the math. Todd falls in love with his tutor, and the two of them begin an affair.