I knocked up my sister-in-law and she wants me keep it a secret.

My sister-in-law is in the process of going through a nasty divorse from her very abusive husband.

He beat her up during labor day weekend '09, so my wife let her stay in our extra bedroom for a few days while things cooled down.

While my wife was at work, her sister cryed on my shoulders and one thing let to another. Yea, yea, I know that I'm an ass for letting my dick slip, but I fell asleep on the couch watching T.V. and woke up with her riding my manhood. I should have tossed her off me right then and there, but was unable to. Moments later I ejaculated hard. It was the only time we ever had sex.

This past July, my sister-in-law told me that she believed that the child was mine and wanted me to pay her a few hundred a month to help her make ends meet. I demanded a dna test and paid for it. The results prove that the child is mine. No one exept her and I know that we had sex and that the child is mine. Not wanting her to tell my wife, I started paying her the money she was asking for. She is using that money to pay for formula and dipers, so I'm not really upset about the situation per say.

Her soon to be x-husband believes that the child is his and is facing a judge slapping him with a support order. My sister-in-law says that we can keep it a secret and screw him for the next 18 years. They are losing their home to foreclosure and my wife already told her that she can come live with us in our large estate.

If I do nothing, knowing what I know, and let the legal system take child support from my sister-in-law's husband, does anyone know if I could get into legal trouble if it ever came out?