In chapter four of The Catcher in the Rye, Holden learns his handsome, popular (but tremendously irritating) roommate, Stradlater, is going on a date. Holden soon discovers this date is, in fact, Jane Gallagher, who Stradlater refers to as "Jean." Holden has feelings for Jane, whose eccentricities—like keeping all of her kings in the back row in a game of checkers—he finds endearing.
Holden is nervous about his going out with Jane because of Stradlater's sexual experience. He does not want Stradlater to make a move on Jane because he fancies her for himself (despite being too awkward to do anything about it). He also worries she cannot handle Stradlater's advances due to the fact that she may have been abused sexually by her stepfather.
Holden, overall, sees Stradlater as a big phony who only cares about getting Jane into bed and does not appreciate her for the special qualities she possesses.