I am sorry to hear your story. I think you should tell. Telling eases the pain and lifts the trauma some. It feels like a huge dark cloud or blanket being lifted. However, be careful how you handle their reaction to your disclosure.
My son disclosed to me when he was 3 years old! I am glad today, that he told me even though my life came to an end when he told me because of whom it was that was doing that to him!
To answer your questions about leaving your kids with someone, I don't anymore! The person who abused my son was the closest person to me and him - so naturally, I am wary of most men! I have not since left my children in care of any man. Subconsciously I have trust issues. Which I have no problems with as I will rather have trust issues than have my son re-molested - I know I couldn't survive that. I will kill the person. One set/series of heinous abuse by one abuser is enough for a poor little boy - if anything ever happened to him or his brother again, there is no debating what will become of the person responsible - he or she will be dead - no question about it!
Daily I worry for the safety of my young sons - but worry achieves nothing! So I pray for their safety!