Jack & Jill (2001)

Jack and Jill are platonic roommates who live in a large loft in Los Angeles. Jill is recently getting over a breakup by dating and having sex with every man she meets. Jack is also getting over his own breakup, but unable to get over the lost love of his life. Despite the two roommates seldom agreeing on anything and their constant bickering with one another, they begin to realize that the one for them may be the one they've been living with all along.