Certainly meddling in others' lives and relationships is not advisable. Ultimately, you will not be successful breaking apart a healthy couple, but if you feel that a couple would be better apart than together then there are things you can do.
3 Steps to Break Up a Couple
If you are trying to learn how to break up a couple, you should study your motives carefully. Why do you want to break them up? If your reasons are questionable, even to yourself, then you should just stop and walk away from any attempt. Breaking up a couple can have unexpected and unpleasant consequences for yourself and for the couple in question. In addition, it comes down to how willing you are to use other people to achieve your own goals, which comes with a measure of its own bad karma.
1. Stalk Their Relationship
You need to first spend time learning everything you can about the couple. Avoid trying to solicit a friendship with the couple directly, instead get to know them through their friends and the observations those friends have about the individuals in the couple. You also want to know the weaknesses in the relationship and those closest to them are more likely to be aware of them than the couple themselves. Be careful though, you are essentially stalking the couple at this point and invading their privacy. If you come on too strong, you could arouse suspicion, jealousy and hard feelings in more than just the two people you are trying to break up.
2. Work the Jealousy Angle
If you find out that one partner or the other has a jealousy issue then you plant the notion that his/her partner is interested in someone else through a third or even fourth party. In most cases, gossip will make its way back to the couple. Consider the tactics employed on a soap opera in which one person wants to break up a couple.
3. Find a Sore Spot and Exploit It
If you have considered the consequences, you have learned everything you can about their weaknesses, and you're still willing to go forward, then now is the time to play on those weaknesses. Remember, the goal is to not actually cause trouble, but to stir up the ripples that result in trust and communication issues occurring between the couple. Learn a source of conflict through your stalking of the relationship and then work that in as much as you can.
If They Don't Break Up
Okay, you've done all of the above and the couple just doesn't seem to be affected or actually overcomes the troubles stirred up between them. You should probably accept that the couple is together and not likely to break up and leave them alone. If the couple is not ultimately meant to be together, then they will likely break up on their own without any interference from you.