I think his really is gay. I think he was kissed by his friend and the girl that night. His friend was blushing over him, which is initial by the artist. The friend don't have feelings for these women, more like a cover up, supressing his feelings for the main character. He is not jealous his "girlfriend" is touching him. He's jealous that he cant have him. I think the "girlfriend" know he is gay, but can't say anything about it because it would break his trust. I don't think she is such a bitch to do anything behind her "boyfriend" back. Its most likely a fake relationship.