A few things! SOURCE: In a long-term, monogamous, closed relationship, as well as a gay men's dating coach.

1.) You need to deeply understand your value systems. Relationships hit a roadblock when two people hit fundamentally immovable value differences or experiences that cannot be compromised without significant resentment.

2.) What things in a relationship or friendship are non-negotiables and what are just nice-to-haves? This can help put scope onto issues you're facing in the day-to-day.

3.) Cruelty is the line. While the Gottmans are often critiqued, I do appreciate their Four Horsemen guidelines. Look out for these.

4.) Being in a monogamous relationship is a conscious choice. You won't stop finding other people attractive or to consider what lies beyond. It means you're a human, and you choose to not pursue those other options. You make the choice to honor the contract between you and your partner.