1. What do we spend the money on?

By far the two biggest and most common things all couples fight about is money and sex. Do we really need to renovate the bathroom (again)? Are we going to send the kids to a $12,000 per year private school or public school? Did you really need another pair of shoes?

2. How often do we have sex?

Therapists call this 'desire discrepancy' when one partner desires sex more often than the other. This problem is very common in long-term relationships and marriages. Of course, there may be other reasons behind this such as dyspareunia.

But when it's not health-related, therapists say that the actual desire discrepancy of most couples is small, couples just imagine it's huge. When asked separately for example, "Ideally, how many times would you want to have sex in a week?" the husband may say 3 to 4 times, while the wife may say 2 to 3 times.

The difference is usually small, but when asked, "How often does your partner want sex?" the husband in that example will answer, "If it were up to her, never! Maybe once a month" while she says If he had it his way, it would be every day!" The perceived difference is much bigger than the reality.

3. Do we have to go to your parents' again?

Family members and extended family play a critical and tricky role in a relationship. This especially plays a big role around the holidays. Decisions like where to spend Thanksgiving can cause all kinds of conflicts. This also includes questions like "How long will your parents stay when they come to town?" and "Where will they stay, will it be with us?"

4. Were you just flirting with her?

If you both truly love one another, jealousy will inevitably come up sometime. It may include questions like, "Why is your ex still friends with you on Facebook?" (It's always hard to explain that one.)

5. Who's doing the dishes?

Another common source of conflict is sharing household responsibilities, especially when things aren't clearly divided. Who's in charge of the finances? Who will take the trash out? To avoid this, have an explicit conversation when you first move in together regarding household responsibilities.

6. Why do you have to [drink] so much?

Fill in the blank with any behavior that greatly impacts you and the relationship, such as play video games, smoke, or watch Netflix. Every single person in a serious relationship wishes their partner would either stop doing something or do something.

7. Are you mad at me? (Are we OK?)

The way couples deal with anger is also a big one. Everyone is different, some are clear and straightforward, passive-aggressive, or aggressive and defensive. That fact is we all have an anger pattern.

8. When are you going to get another job?

It's always stressful to quit or lose a job. Most couples experience this at some point in their relationship. When one partner loses their job, there's a very fine line for the other partner to walk between being encouraging and being supportive. You try to be understanding, but there is also the financial responsibility that needs to be taken care of.

9. Why are you still working? (Why aren't you spending more time with me)

When your significant other has a job, did you ever find yourself negotiating how much time the two of you spend together? The article from Fast Company nails it: "What To Do When Your Crazy-Long Hours Are Ruining Your Relationship." It begins with a few common refrains:

• "So I assume you're not coming home for dinner again tonight?"
• "Didn't you have to work last weekend, too?"
• "Gotta say, I don't feel I'm much of a priority lately."

The amount of time your partner spends at work can play a big role in the sense of your importance in their life.

10. What are you doing on your phone?

Social media, technology, and distracted thinking. They are the consequences of today's constantly-connected world, and it has a big impact on a couple's relationship. Feeling ignored can be painful, which is the feeling one feels when their partner is on their phone when spending time together.

Smart couples create rules to contend this and protect their couple-time (no phones after 9 pm; no phones during dinner, etc).