Okay, I need a really good non-cliche reason why my love interest would leave the main character. I'm stuck between having her discover something horrible about him, (like, he was her brother's best friend, and I've thought having him be the one who got the brother the drugs he overdosed on) and sending him away, basically. Or having him leave for some noble reason. Also, I'm drawing a blank on how to write the love part of it. I want it to be a very intense love, I have them making out the second day they know each other, and it's a very deep love, so they're instantly comfortable with each other. But, I am very worried that it will start to sound cheesy, and fluffy, so tips? Also, what are some cliches i need to avoid with this sort of thing. I suppose it will be a Young Adult Novel, the main character is 18, and the dude is 21.