In the movie, it is not specifically stated what happened to Gordon. However, in the screenplay by Refn, Julian kills Gordon when Gordon brings up that he had slept with Julian's Mother.

Tur-kue-kwam-fun (You are my dream) Tur-kue-kwam-fun, Nai-Chai-Chun (You are my dream, in my heart) piang-kwam-fun-tee-san-klai (A dream, a faraway dream) Dung-kwa-dao-bon-fah-klai Mai-mon-chai-cha-qua (like catching a star in the deep sky, I'm not sure I can catch it) Preab-dung-dog-mai-hang-kwam-hwang (like a flower of hope) mee-kwam-fun-tee-kwang-yai (having a big dream) haag-mae-tur-piang-kao-chai (if you just understand) chan-mon-chai-saag-one (I'm sure one day...) cha-long-kwai-kwa-ha-come-tob (I'll try to find the answer) fun-kong-jing-saak-krung (I wish dream will come true just once) cha-mee-kwam-rug-hi-tur-yang-ha-cry-ma-preab-muean (I'll give you my love like no other) cha-long-kwai-kwa-ha-come-tob( I'll try to find the answer) fun-kong-jing-saag-krung (I wish dream will come true just once) cha-mee-kwam-rug-hi-tur-yang-ha-cry-ma-preab-muean (I'll give you my love like no other) mae-tar-me-tur-you (just I got you) me-piang-rao-song-rug-gun-you-kaang-kiang-gun-sa-mure (there will be us, loving and standing side by side) nai-chai-luem-plure-la-mure-tuen (but I'm daydreaming) fun-young-coin-log-lon my dream keeps haunting me hi-chai-me-tae-tur (you are in my every single breath) mae-mai-me-tur-you (even you're not here)