It’s common to spend so much time in the workplace that co-workers feel like family — but experts say it’s best to tread lightly when mixing your social life in with your job.

The golden rule to remember is that unlike with most friends made in life, when it comes to socializing with co-workers, “if it wasn’t for the job, you and that person wouldn’t be speaking to each other,” noted Akida Phillip, a career services coordinator at the New York Career Institute.

We asked Phillip and other experts about the do’s and don’ts of mixing work with pleasure.

Making friends

When it comes to building friendships with your co-workers, Julie Holmes, an NYC-based life coach, prefers to err on the safe side.

For the sake of your career, it’s best to leave work friendships at work, she said.

“Let’s say there’s a possible promotion for you, then all of a sudden you’re the boss of your friend,” Holmes explained.

And in terms of what’s OK to chat about, keep it light, she added.

“It’s important to avoid talking about people in the office. Avoid talking about your boss,” Holmes warned.

However, Harper Spero, an NYC-based lifestyle and career coach, said making personal friends at work is common, and added that she is buddies with some of her clients.

But, like with any relationship, it’s best to take it slow, she said.

“My thought is that it’s important to build trust with your co-workers before you start telling them your deepest, darkest secrets,” Spero recommended.

Social events

Going out for drinks to take the edge off a tough day is perfectly fine, our experts said, but use discretion in those situations too.

A good practice is to behave like you would if you were enjoying downtime in the office, according to Phillip.

“If you go out with your work friends, remember that they’re your work friends and you have to be cognizant of what you’re saying because you’re really still at work,” he said.

Additionally, Spero suggested keeping a low profile.

“Don’t go to every single event or happy hour and become the drunk guy or girl at the company,” she said. “You don’t know what’s going to get back to the workplace.”

To turn down a social invitation from a co-worker, or boss, be gracious and vague, added Holmes.

“I would say, ‘thank you so much for this invitation, I’m really honored,’” she said. Then add, “‘But as it turns out, I have a prior commitment,’ and keep it at that.”

Damage control

Any time things get personal, feelings can get hurt — even from work friendships, our experts said.

But while the temptation might be to tell a manager about a grievance, Holmes feels it’s best to confront that person directly.

“Your boss isn’t there to manage your personal relationships with your co-workers,” she said.

If someone says something hurtful, Holmes recommends telling that person, “’I would appreciate it if you could avoid those kinds of comments because they affect me emotionally.’“

Before you do that however, take time to cool off, Spero added.

“It’s extremely important to give yourself time to pause and acknowledge how you’re feeling before [confronting] your co-worker,” she said. “Communication is key and it’s impossible to remain friends and be productive at work if there’s tension between you.”