In Mullinax's study, a majority of participants revealed that they didn't tell their partner about their crushes.
But MLU found that open communication is crucial:
1. Honesty is key! "Keep open and honest communication at all times, and work through it together," he wrote. "Don't hide your feelings from your partner, even if you want to protect the other person. You might not want to talk about it, wether [sic] you have the crush or they do, but you HAVE to communicate. You HAVE to know what your partner is going through at all times. Work through it together, and you'll come out together."
2. Set boundaries. "Don't be alone with your crush (like never meet up for coffee), because while she can't avoid working with him, she can avoid seeing him other outside of work. Meeting up like that is a chance at taking intimacy to a deeper level," MLU explained. "You might want her to cut off ties to him entirely, but often that's next to impossible to implement. Think of this like a 'soft' cutting off ties. Think about it, you have your 'work friends,' and then you have your 'friends you hang out with.' It puts a barrier there."
3. Be careful what you tell your crush. "Never complain or joke about your partner to your crush," MLU warned. "Even the most innocent joke can indicate you are not happy with your relationship."
4. Focus on your relationship. "Spend more quality time together," MLU suggested. "Turn off the TV, get off Facebook & Reddit, and play board games or go for walks. I always think the free dates are more intimate than going out to dinner & drinks, because that can feel like throwing money at your relationship, but those can be fun, too."
5. Never give an ultimatum. If your relationship is strained, don't push your partner over the edge.
"This is a very common tactic in these situations, and I think it only does harm to the relationship," MLU said. "It might seem like a good test of their devotion to you, but when you are emotional (which you definitely will be if you are going through this), please consider you might not be setting a reasonable ultimatum. More importantly, giving any ultimatum (however reasonable) tells your partner that you value your needs over your relationship."
Ultimatums are generally a bad idea—that puts the onus entirely on your partner instead of keeping the relationship a partnership.