Of Love and Desire

Of Love and Desire is a 1963 film directed by Richard Rush.

Steve thinks that Katherine is what he expected but ends up developing a crush on her. As their relationship develops, Paul gets upset and reintroduces her exboyfriend Gus Cole to her to lure her away from Steve. Halfsiblings Katherine and Paul are carrying some emotional damage from the past which they need to work out.

Source: Wikipedia