Is it my place to correct my sister in how she raises her children?

My older sister has always been a bit more wild than I am. We shared a room until the day she moved out of the house so I know a lot about her. She would shoplift Mars bars from the newspaper stand she worked at and brag about it to me. She cheated on homework with her friends in front of me. She had no problem sneaking boys into the room at night even with me laying in bed beside her. Trust me, she is a little loose in the morals department. Nowadays we are both married and have children. She has 3 teenager boys, two of which are twins. She has NEVER been good at guiding them or punishing them when the need it. Ever since they were kids she let them do whatever they want. Once time one of them put a cat in the freezer, shaved part of that same cat and even worse is that once they threw eggs all over my kitchen and she didn't say anything more than 'hey, boys'. Thats it. Now that they are teens they are doing STRANGE things only a child raised in such chaos would do. They openly brag about masturbating! They have a 'cumtest' (their words, not mine!!) where they see who can ejaculate in the strangest place. I have never known a single human being who would have such a sick contest with his brothers. My sister says its just boys being boys. They talk about it openly. The breaking point was when they told me about this at our dual mother's day brunch. We were at a brunch hall and they bragged that one of them masturbated in the urinal at the brunch hall! Another said he masturbated IN MY HOUSE once, one of them (forget which casue i blocked it from my mind) said he masturbated into a book at the library and put it on the shelf. I DO NOT GET THIS BEHAVIOUR! I think these children are severly troubled. I have talked to my husband, who is a manager, and he said it may be time for me to step in. Our parents are no longer with us so it is my duty, even as the younger sister, to tell her enough is enough. I think I should call the school and tell them about the book, tell my sister to raise her kids better and ask that her kids be sent to a psychology professor. Does this sound appropriate or will she blow up at me?