Graduate school is hard for couples to endure. Temptation abounds. You live in penury among ambitious young (for the most part) adults, speaking a peculiar argot, attending what feel like mandatory social events and excursions steeped in alcohol, with superstars dropping in and strutting among you. Plus, there are all those fraught moments that only a fellow student—another insider—can help you soothe. Meanwhile your significant other is likely supporting you, often at a less-than-ideal job in a less-than-ideal place. Resentment builds. Sloughing a partner is easy and commonplace.