We all have been in a situation where we look back and say we should've known our ex was an abuser, a cheater, or a jerk. It's easy to do in hindsight. I know because I've done it at least 18 times.

The reality is that we may have seen the red flag but we justified it in our mind to be a little more pink than red because we liked the guy. Sometimes this can be OK, but be honest with yourself and if the flag is, in fact, very red, get out before it's too late. Here are five red flags that must not be ignored.

1. Too rough. If even when playing around he grabs you too hard, twists an arm, or pushes you, he's no good. A respectful person will never try to hurt his partner, even when they are just playing around.

2. "Who's that guy?" syndrome. Chances are that if you get 20 questions over seemingly unimportant parts of your day that he is insecure. Everyone is a little jealous, even in a healthy relationship, but know the difference between a little and a lot of jealousy. If he puts you down or accuses you of things, then consider it a red flag.

3. Listen to your friends. Your family and friends want what is best for you. They love you. Although there are always exceptions to this rule, at least consider what those close to you have to say about your boyfriend. Since they only want you to be happy, there is probably a good reason for their feelings.

4. You don't do the things you used to. Every time we fall in love our priorities change and so it's natural that you would see your friends less or spend less time on your hobbies, but it's not healthy to eliminate these things altogether. If your significant other prevents you from spending time with your friends, or makes you feel guilty for even wanting to spend time on your own, consider this a red flag.

5. One minute he's sweet, the next he's scary. Instability makes you worry about what kind of mood he'll be in once you get home or about rearranging your day just to make him happy. The reality is that you should be with someone that is stable and who treats you well all the time.

Women are just as guilty of presenting these red flags, and of course there are far more red flags to heed than those that I list here. Since this list just scratches the surface, visit DatingTales online dating guide for more tips.

Dating Products on our marketplace

About the Author: Sara Musfeldt operates a blog filled with dating stories and dating profile tips for everyone. Sara has also created an online dating advice to help singles everywhere find love.