If you find yourself making statements such as, "I wish I had a boyfriend to take me to dinner," "All these people in relationships make me sick," or "Why would I even want to go to the prom?" you may be the bitter single friend of your group. Psychologist Randi Gunther suggests in her "Psychology Today" article "Bitterness: Love's Poison" that bitterness is a learned behavior, often stemming from unrealistic expectations, broken promises and depression. Learning to identify bitter attitudes and behaviors is the first step toward making emotional and social improvements that in turn may break your single streak.

Segregating Your Friends

Labeling your friends as "single" or "taken," while intrinsically harmless, draws a line between you and your friends in relationships. Pointing out that you don't hang out with one friend as much because she's "always with her boyfriend" sends the image that you are bitter over that friend's relationship or your lack of one. Include your dating friends in your events to avoid coming off as bitter or jealous of their relationships.

Others Treat You Like You're Bitter

What you believe about yourself can influence your behaviors and how you treat others, which in turn can impact how others treat you, reaffirming your initial belief, according to clinical social worker Allan Schwartz in "The Self-Fulfilling Prophesy: Making Expectations Come True" on MentalHelp.net. This effect is twofold, those who believe positive things about themselves tend to receive positive feedback from others, while those who are bitter may receive feedback that reaffirms their negative beliefs. In other words, if you feel abandoned by your friends during prom season, it may have to do with your bitter attitude toward others or toward being single.

You Draw Attention to Your Relationship Status

Chances are that your friends and family are aware of your dating life. Pointing out that you are single, or drawing attention to the fact that you are not in a relationship, can be interpreted as being bitter. Even otherwise harmless comments such as, "Your boyfriend is so thoughtful, if I had a girlfriend I'd buy her flowers as beautiful as yours," can come across as desperate or bitter.

Boycotting Romantic Holidays and Events

Let's face it, no one likes to be single on Valentine's Day. Even if you feel spiritually and emotionally whole without a significant other, pointing out how much you hate Valentine's Day or that you wouldn't be caught dead at prom reinforces the idea that you are the bitter single friend of your group. Instead of boycotting the event, indulge yourself on Valentine's Day or ask another single friend to prom, you just might have fun.

Being Passive-Aggressive

If you respond to your friend's comment about her great date last weekend by saying, "That must be nice. I wish I were on a date," you are being passive-aggressive and bitter. You can avoid this sentiment by talking about what you did over the weekend or even asking her to elaborate on her date.

Placing Blame

Bitter individuals often believe that their situation is the result of other people's actions, according to an interview with psychologist Carsten Wrosch in "The Atlantic" article "The Psychology of Bitterness: 10 Essential Lessons." While more adjusted individuals might think, "Maybe I'm single because I'm looking in the wrong places, maybe I should join a new club to meet someone," a bitter person may think, "I'm only single because there's no one worth dating at this school anyway."

Rationalizing Your Relationship Status

"Men are all the same," "Guys only want me for my body," and "I don't have time for a girlfriend anyway, SATs are coming up soon," are all examples of rationalizing why you're single. Not only does this draw attention to the fact that you're single, but it blatantly disregards the relationships of your friends and family. On one hand, this rationalization can be empowering in moderation, but on the other hand, your friends may misconstrue your daily affirmations as an excessive way of coping with bitterness and jealousy toward dating.