<p>On his first day teaching math at a community college, Chris Reuben gets an unexpected and unwelcome blast from the past: one of his students is his former shipmate… and ex-boyfriend.</p><p>Justin Hayes isn’t looking for a second chance when he signs up for his ex’s algebra class. All he wants is a passing grade and maybe a shot at mending fences with the man he loved—and hurt—while they were deployed three years ago.</p><p>Pain, guilt, and bitterness aren’t the only lingering feelings, thoug...