When I was in high school, I was in an uncharacteristically long-term relationship, as far as teenage romances are concerned. He wasn't my first boyfriend, but he was my first real boyfriend. He lasted more than a month, for starters, and he was the first person I actually loved. Like, really, really loved. But while many people oohed and aahed over our four-year-long relationship, there was something sinister lurked beneath the cute couple photos and playful banter. He'd cheated on me. Like, a lot.