only my theory, but I suppose it relates to how Jordyn had his "ideal" in his first (relationship) partner - absolute bottom, Twink, younger - but then reverted "back" to the complete opposite of that with Owen (his try-out aka one night stand, who he choose for that reason in a way, so it would be JUST a one night stand). Owen is more buff, a top and definitely more of a sorta of "alpha" guy. There is no real reason on the surface for Jordyn ultimately choosing Owen (ergo WHY is it HIM?), but they're just attracted to each other. So Jordyn ends up with something completely different from what he originally envisioned and that's just how love works sometimes. We may have this ideal in our heads of what we want our partner to be/look like, but at end, you just fall for someone and can't rationally explain that. You're attracted to whoever YOU feel attracted to, no real reason.
Is it because I miss out some part ? can someone explain to me, how does the title relate to the story?