what are you supposed to do when you found out your son in law is cheating?

Philippines
@Erssyl (617)
November 17, 2008 12:54am CST
I would like to ask your good advice this time especially those who had encountered the same problem I have now.My son in law is cheating on my daughter who is now 6 months pregnant and in a very difficult situation.Her bag of water is leaking and she's supposed to be in bed rest with no stress.I found out from the sister of my husbands grand daughter of his brother and my son in law is still having an affair which we thought was over for a year now.Yesterday I found out from her sister that they are now living secretly.He is a doctor can I file a case against them.What move am I supposed to do now.My heart seems to be exploding from anger.Is it right for me to hurt him by giving him one big punch...Please share your opinion.