Want to avoid ending up on the proverbial couch at any point in your relationship? Watch your words. Below, psychologists and relationship experts share 10 things you should never say to your S.O.

1. "Why don't you ever do what I ask you to do?" 

You're setting yourself up to fail whenever you throw out all-or-nothing, black-and-white statements like this, said Marcia Sirota, a psychiatrist.

"It implies that they only ever do things one negative way, which couldn’t possibly be true," she said. "Your spouse will feel pigeonholed and will become defensive and possibly even resentful toward you." 

Instead of generalizing, Sirota said you'd be better off pointing to a specific, singular example of the behavior you find annoying. 

2. "You're being just like your father/mother." 

It doesn't matter how healthy a relationship your partner has with his or her parents: comparing them to dear old dad or mom mid-argument is a particularly low blow, even if the comparison is true, said Megan Fleming, a psychologist and instructor of psychology at Cornell University in New York. 

"We've all had certain models of behaviors that we can’t stand and sometimes, we've unconsciously or even consciously adopted these reactive ways of responding in frustrating moments," she told HuffPost.

Instead of insulting your spouse and your in-laws through comparison, Fleming suggests you work as a team to identify the passed down, negative behavior patterns. Once you've figured it out, your spouse can work on it. 

3. "We need to talk but now is not a good time."

If you keep putting those big relationship conversations on hold, you have to wonder: Will there ever be a good time to talk? What's more, the anticipation of not knowing what's going on is bound to make your partner feel uneasy, said Susan Krauss Whitbourne, a psychologist who writes Psychology Today's “Fulfillment At Any Age" blog. 

"It creates anxiety without providing an avenue for alleviating that anxiety," she explained. "It's also a controlling statement. If you feel the need to talk, then wait until you have the time and ask if your partner has whatever length of time you need." 

4.  "Stop talking." (Or its uglier alternative: "Just shut up.") 

If you find yourself telling your spouse to "shut up" mid-argument, go directly to jail, do not pass go, and most definitely do not collect $200 -- you've made a huge slip and don't deserve it.

"This phrase is controlling, disrespectful and kills communication," said Kurt Smith, a therapist who specializes in counseling men. "The lifeblood of marriage is love and communication; this phrase destroys both." 

5. "Will you please just relax!”

Unless your goal is to prolong your partner's anger during an argument, don't tell them to "calm down" or "relax." These phrases don't bring stress levels down -- they're more likely to trigger hostility and make you look like the bad guy, Sirota said. 

"These statements imply that your partner is unable to control themselves -- it feels like you’re treating them like a child," she said.

A more helpful phrase is, "Hey, let's both try to take a deep breath," Sirota said. "That will be heard as a gentle reminder, whereas the other phrase will be heard as a put down." 

6. "I want a divorce." 

Regardless of how mad you are, don't claim you have a divorce attorney on speed dial unless you really do. While this may seem painfully obvious compared to some of the other phrases on the list, you'd be surprised how many couples let the D-word slip during counseling, said Smith. 

"For some couples this is a common threat they use, but never act upon," the Northern California-based therapist said. "When you say this, it destabilizes the relationship and makes it unsafe, which paralyzes growth and change."

In other words, don't make empty threats or issue ultimatums unless you mean business, Smith said. 

7. "How do I compare to your ex?" 

Asking questions about your partner's ex and how you compare is very risky, said Fleming. Sure, you may feel flattered by how you stack up -- but there's an equally good chance you'll be put off by their response. 

"This question just sets your partner up," she said. "Don’t sabotage yourself or your relationship in this way." 

8. "You don't bring me flowers anymore." 

Flowers in this instance are a stand-in for just about anything your S.O. used to do: You don't kiss me on the forehead before bed; you don't send me cute text messages throughout the day. Whatever your complaint is, issuing it in a declarative, accusing way corners your spouse and makes it difficult to respond, Krauss Whitbourne said. 

"These kinds of statements are unrealistic and a bit passive aggressive," she said. "It make your partner feel defensive."

9. "We never should have gotten married." 

This is on par with the casual divorce threats, Smith said. 

"Characterizing the whole marriage as a mistake stings to the core," he explained. "This is another statement that is said to hurt and comes from the speaker's own hurt. It's almost never really meant, but wounds very deeply."

10. "Why can't you look a little more like him or her?" 

You may think David Beckham looks amazing with an undercut but suggesting your spouse go out and get the same haircut in a heavy-handed way is not likely to go over well, Krauss Whitbourne said. 

"Comparing your partner to someone else is never a good idea, and it's particularly bad to add in an accusation or criticism along with the comparison," she said. "Even if you're asked, 'Is X prettier/more good-looking than me?' stay away from judgments that put your partner in an unfavorable light. There's nothing to be gained other than to create hurt feelings. You can give an honest answer but don't forget to compliment your spouse's look, too."