DISCLAIMER: these are just broad generalizations from commonalities we noticed while reading slash, we're not saying that all slash stories are so predictable or even that these things are bad.
1) Lance is always gay. Doesn’t matter if he’s the main character or not, he is gay...or at least bi.
2) JC is always bi. Never gay, never straight, always bi.
3) JC must never know that he is bi at the beginning of the story, he must figure it out from his growing feelings of desire for another bandmate.
4) Chris is always completely cool with everyone being gay and is always there to “talk”, despite his inherent crazy nature.
5) If there is abuse in the story, Justin is the abuser.
6) Lance is usually the one that Justin is abusing.
7) Lance is the only one who is ever a victim of abuse, by Justin or an outside character.
8) The other bandmates don't need to be told of an inter-band relationship, they just "know"....from 5 years of sharing a bus, or something.
9) Everyone's eyes tell a story. Everything a character needs to know about how someone feels, they just look in their eyes, it's all there.
10) At least one member of the couple, whether they have JUST discovered they’re gay or not, always has plenty of condoms and lube nearby.
11) Why do they always have sex facing each other? I would think that it would be a little more uncomfortable and difficult......then again, they are limber young men.
12) The road to true love is always a rocky one. One member of the couple must wrestle with their newfound sexuality...for a long time, before coming to terms with it.
13) The parents are completely okay with their sons being gay 99% of the time, often being quite happy about it.
14) The cause of many breakups is the secrecy, the fact that they can’t be with each other out in public or reveal their relationship to the world, etc., which makes for a nice social message angle to the story.
15) If JC is in the story and needs to do some serious thinking, he must be put at a piano, otherwise he will not be able to figure out the solution to the problem.
16) In alternate universe stories: Justin is always a solo singer, JC is a music producer, Joey is an actor, Chris is most often a teacher, and Lance....well, Lance doesn’t really do anything. He just sits around pining for whoever he loves and waits for him to come around. One would assume that he is independently wealthy and does not need to work. Or else he is a farmer, rancher or cowboy/bullrider.
17) The guys always share hotel rooms, even though they’re filthy stinkin’ rich and don’t actually need to, and don’t share rooms in real life anymore.
18) At least one member of the couple must struggle with the religious debate, but soon realizes that God loves everyone, regardless of sexuality, once again, making for a nice social message angle.