Summer flings sometimes lose their sizzle, and Millennials’ relationships with their employers are often just as fleeting.

You know the story: Employer meets Millennial; employer hires Millennial — but they don’t always live happily ever after.

Say what you will about Millennials, but this crowd has high standards. Raised on a diet of affirmation with an emphasis on personal contentment, Millennials seek jobs that offer fulfillment and growth.

If you don’t invest in your relationship with young employees early, they may fall into the arms of the next attractive employer who gives them a call.

The Elusive Catch

Millennials bring creativity, youth, and ambition to a company, making them attractive prospects for any organization. But this demographic faces the challenge of being desirable employees who often can’t find a job.

An unenthusiastic job market and mountains of student debt haven’t dampened their spirits in the slightest, though. They may have to settle for a less-than-stellar entry-level position, but they won’t hesitate to abandon a job of convenience for one that aligns with their core values as soon as a better opportunity presents itself. Millennials are always looking for the next opportunity to move up and get closer to their dream job.

That eager new recruit may have stars in his eyes when you offer him a competitive salary, but money won’t buy his love — at least not forever.

How to Avoid the 3-Year Itch

No one wants to start a relationship that already has an end date, least of all employers. But research shows that Millennials typically leave a job within three years. The cost to hire, train, and replace these employees is typically more expensive than hiring someone more experienced, so it’s worth considering how you can entice them to stick around.

Implementing an attractive onboarding process with ongoing mentorship and development opportunities is key to retaining Millennial employees. Here are three key points to consider for creating loyalty with these hires:

Be thoughtful in your approach to training. Just as you wouldn’t take your vegan sweetheart to a steakhouse, you shouldn’t count on training Millennials as you’ve trained Gen Xers and Boomers.

Orientation and training are often synonymous with boring. When designing your training program, consider how young employees prefer to learn and communicate (with smartphone apps and online tools, for instance). Building training programs using resources that are familiar to them will help you engage their interest and earn their respect for being a forward-thinking company.

Adobe’s new employee program has upgraded the traditional lecture-based training process to an interactive web presentation and discussion. This allows new staff members to be part of the conversation right off the bat.

Revamping your training programs doesn’t just benefit your Millennial hires, though; a solid onboarding process will help you hook employees of all ages.

Help them envision a future with your company. “Where do you see us in five years?” is the question free spirits dread most on a date. But just because they aren’t typically looking for a serious relationship doesn’t mean you shouldn’t make an effort to show Millennials what a future with your company could look like.

Thirty-seven percent of Millennials believe building a career provides a sense of accomplishment (compared to 26 percent of Baby Boomers), so implement mentoring and career-building programs from day one to show you’re serious about a long-term relationship.

PepsiCo pairs Millennial hires with executive sponsors through its Conn3ct mentoring program, which helps new employees see the long-term opportunities with the company. This pairing gives new employees a chance to be heard and a way to feel accepted in office culture so they feel productive from the first day.

You can also invite young recruits to participate in company discussions and projects early on to make them feel valued. Connecting young blood with senior management helps inject fresh, innovative ideas into leadership circles while giving new employees a voice.

Don’t suffocate them with the traditional 9-to-5. Ask any commitment phobe, and she’ll tell you that sometimes she just needs space. Millennials don’t want to be suffocated by a traditional relationship — even the 9-to-5 sort. They appreciate and expect a good work-life balance, and flexible work options help achieve that.

You don’t have to invest in sleep pods or any of Google’s other outrageous perks, but you can consider ways to boost productivity and employee happiness by offering flexible work options.

American Express categorizes staff workspaces based on team members’ roles in the company and the kind of environment best suited to their circumstances. Its BlueWork program has helped establish these more tailored environments, and these changes have helped increase productivity rates and saved the company between $10 and $15 million annually.

If your company has been hurt before, bringing on Millennials may seem like a risk. But these young employees ultimately want what anyone wants in a relationship: personal fulfillment, appreciation, and the promise of a bright future together.

By investing in the relationship with mentorship and career development opportunities, giving Millennials their space, and being thoughtful in your approach to training, your company and Millennials will have a better chance of growing old together. By investing in the connection between mentorship and career development opportunities, you’ll be more likely to maintain a strong relationship long after the honeymoon ends.