Can you file a lawsuit against people who are getting into the marriage?

You may be able to file a lawsuit for defamation of character (e.g. slander) if you can prove tangible damages caused by an individual making false statements about you. This is a huge stretch, however, for the situation you are describing.

Please understand that the civil court system does not exist to resolve your relationship issues, however frustrating they may be to you. You may find a more satisfying, meaningful resolution through marriage counseling or simply by excommunicating the individual in question from your life.