One of the most common pieces of marriage advice is to “marry your best friend.”

While the idea sounds beautiful—marrying someone you can laugh with, confide in, and trust completely—it’s not always the best approach to a lifelong commitment.

While friendship is an essential foundation for a strong marriage, there are some potential downsides to marrying your best friend. Here are five reasons why it might not be the perfect match.

1. Lack of Romantic Chemistry

Friendship and romance operate on different wavelengths. While best friends share deep emotional bonds, that doesn’t always translate into physical or romantic attraction. A strong marriage requires both emotional and physical intimacy.

If the relationship feels more like a sibling bond than a romantic partnership, it could lead to dissatisfaction in the long run.

2. The Risk of Losing Both a Marriage and a Friendship

If the marriage doesn’t work out, you don’t just lose a spouse—you also lose your best friend. This can be even more heartbreaking than a traditional breakup because the person you once turned to for comfort and advice is now the one causing pain.

The risk of losing both relationships can make conflicts even more difficult to navigate.

3. Over-Familiarity Can Lead to Complacency

When you marry your best friend, there’s a chance that comfort and familiarity can turn into complacency. You may stop putting in effort to impress or excite each other because you already know everything about one another.

The excitement of discovery—learning new things about your partner over time—can be lost when you’ve already shared everything as best friends.

4. It Can Blur the Lines Between Friendship and Marriage

A best friend is someone you vent to, joke around with, and sometimes even be brutally honest with. However, marriage requires a different level of care in communication.

If you continue treating your spouse the same way you did as friends, you might struggle with setting boundaries, handling serious conflicts, or maintaining the level of respect and effort needed for a romantic relationship.

5. You May Not Challenge Each Other Enough

Best friends often validate each other and provide emotional support, but a successful marriage also requires personal growth and challenge.

A partner who always agrees with you or avoids confrontation might not push you to grow in ways that a spouse should. A healthy marriage should involve constructive disagreements and growth, not just comfort.

While marrying someone you have a strong friendship with is important, it’s not always wise to marry your best friend. Marriage thrives on a balance of friendship, romance, and personal growth.

If the relationship leans too far into just being “best friends,” it could lack the passion, challenge, and mystery that keep a marriage thriving.

Instead of focusing on whether someone is your best friend, focus on whether they are a great life partner—someone who loves, supports, and challenges you in ways that make both of you better.