This is a very hot discussion not only between teenagers but also adults.

If you're married, and committed, and you kiss or smooch or even more (ie, get physical) with someone else, does that mean you're in a relationship with two people?

This is a good indication that you're not happy with your current partner, and you're just using the other partner as a scapegoat. This doesn't make any difference whether or not you're intending to take the second relationship further. If you're in a committed relationship with someone, you ought to give them the respect they deserve (and you ought to preserve your own integrity) by letting them know you're not happy. Life's too short to be unhappy.

Today, there are cases where there are people getting married as per parents choice. They try hard to understand each other and try and get close and stuff but nothing turns out as they thought. They end up being unhappy at the end. So now they think of a something else and they consider entering into another relationship. The best thing that gets into their mind is date, this not only make them curious and happy but also an urge to get satisfaction themselves in terms of lust. This is a dangerous road to travel!

There are even instances where they marry to their loved ones (even if their family doesn't want them to) but after a while everything turns out a mess when they see the reality of love without a means to survive.

The lust fades away and they may go ahead with dating other people. For many even today after being married or committed, still lives with the philosophy or a statement of life "Variety adds spice to life." So for them everything is fair up till and until their partner comes to know about it. They want to achieve new and still love to be in safety zones. It's not possible to have your cake and eat it too.

Sometimes these second partners turn out to be more than just a date, and this adds to the confusion. But let me tell you from experience: It's hard enough getting it right with one partner, let alone two. Consider the jealousy and envy involved. It's often just not a happy environment in the long term. Better to make the right decision and deal with the relationship you already have, rather than lose both.