Tell my abusers wife?

Q: when I was 10 and my cousin was 13 he molested me.  It only happened once and we didn't see them very often so I never said anything, but it definitely happened.  Recently I found out he is going to have a kid and I'm worried that if I don't say something he could do this to someone else, but if I do say something I could ruin his marriage.  Or my whole family could accuse me of lying and I could end up causing a lot of drama for no reason.

A:  continued silence is not an option.  This is not because you have to protect the world from your cousin, that is honestly beyond your control.  It is because you owe it to yourself to confront this issue and not be shamed and trapped by it when you did northing wrong.  

No matter what you do from this point it is likely to be painful for you and at least somewhat disappointing in the outcome so it is important that you have a therapist or close friend who knows everything supporting you through the process.

In a perfect world you contact him and say, "this happened and it caused me a lot of pain.  I need to know it is never going to happen to anyone else and that you are working through what ever caused you to do this in the first place (there is a significant chance that he too was abused at some point prior to molesting you).  

He would then acknowledge what he did, ask for forgiveness, get into counseling and tell his wife about his life experience.

That could happen, it is not as crazy impossible as it sounds because he may be carrying a lot of pain about this too.  BUT the more likely scenario is that he falls short of that ideal.  Most likely he will simply deny.  

You need to be prepared for that and ask yourself if you are willing to contact his wife if he won't.  I think there are significant cons to using the threat of telling his wife to force him into therapy.  You will never know if he is really attending or what is being shared there so if you have any doubt that he is facing his actions honestly letting his wife know what happened so she can make her own decisions is a path you will likely have to take.  

She is very likely to deny and be angry with you.  People tend to shoot the messenger.  This is a man that she loves and they are about to take on the biggest challenge of their lives together so do not expect her to thank you.   At the same time if you were in her position I think you would want to know.

Hopefully this was one confused act of an early adolescent.  There are probably hundreds of thousands of this kind of abuse perpetrated every year that are never reported so our statistics tend to suggest that perpetrators tend to be continual abusers buy my hunch is those are just the ones we catch.  Regardless, we can't take a chance and you do not need this on your mind anymore.  In order to be free of this you must confront and probably report on.