Jon didn't consider himself gay, but rather bisexual. He was attracted to both sexes, which could be stressful at times. Especially when he would see a couple holding hands in the school corridor and not be able to decide who he'd enjoy having sex with more. He had gone on a date with another student who was gay, his parents thinking it was two boys hanging out. There was definite chemistry between them as they had gone from kissing and fondling to sucking each other's cocks. But it stopped at that point because the other student hadn't come out to his parents yet and wanted to do that first. Jon had been ready, but accepted assuming they would go the rest of the way next time. It devastated him when that student's family moved out of town the next month. These memories came back to him as he grew angry over his dad's words. He formulated, as much as his anger let him, a wish to both punish and teach his dad, and finally get what he had missed out on.
"I wish, the next time he sees me, my dad will become as sexually attracted to me as he is to mom, then just as much in love with me as he is with her, and willing to show it physically, until I wish otherwise."
Jon immediately knew he'd probably regret this later. Then he thought of his mother and her likely reaction. He then made a wish to deal with that.
"I wish, if my mom finds out about me and dad, she'll be perfectly accepting about it."
Now, all he had to do was have his dad see him to start the wish.