The commonly accepted definition of "third wheel" is, "One who deters the socialization of a couple, perhaps when being invited out of pitty or through a feeling of duty. This person may be eased into the situation by being allowed to stay in an envirnment he or she has become accustomed to (perhaps a kitchen, where the third wheel can bake cookies for the couple.) The third wheel may feel uncomfortable about watching the couple canoodle on his her her sofa, but none of this is taken into consideration. Ex: Emma is such a third wheel/ cock blocker." (source: http://www.urbandictionary.com/define.php?term=third%20wheel)
Try to rethink you idea of the third wheel, they shouldn't be seen as cock blocks in social situations having a third wheel is actually beneficial. When you have a third wheel, the couple may seem less intimidating to outsiders and therefore more approachable. Going out with a couple is fun, it gives you the freedom you want but the structure you need. Couples are reliable, you know they won't ditch each other and they're have an exit plan and make more responsible decisions than hanging with other singles. So re think your dating strategy, and try going out with couples, it allows for the best combination of networking ease and social freedom.
Female Third Wheels:
They may not even be considered a third wheel by the couple. But the female may often feel left out and feel like a third wheel. But compared to male third wheels, female third wheels proves more useful in social situations opening the door to many more social experiences. They are way more useful in social situations that can open the door to interactions with other circles and to play match makers with your mutual friends. It's a win- win-win situation for the couple, the "third wheel" and your mutual friend!
Male Third Wheels:
When you have a single male as a third wheel, it's still not bad. The couple may act as an incredible "wing man", it's easier to have a couple as a wingman because it's easier and more relaxed to approach a group of women that way. Two guys commonly appear predatorial to single women and as soon as they are being approached, they feel like field mice with a swooping hawk above. Couples balance the male to female ration and neutralize tense social situations. If your target, the women you are trying to whoo, is around a couple which activates the relationship schema, in psychology we call this a "prime," making her feel all warm and fuzzy inside. When couples are around single women it ignites many emotions from jealousy to annoyance or appreciation which makes her think about relationships. The popular notion that weddings are the easiest place to "get laid". The same rationale behind that hold true here, being around couple often makes women more likely to be open, hookup, or maybe even agree to a date.
