My 11yo son asked my 6yo daughter to show him her genitals and to blow him.

[aryanpandeyim]

My 11yo son asked my 6yo daughter to show him her genitals, and asked her to blow him. He even showed her a porn video, to demonstrate how to blow. My daughter told this to me in detail, unaware of the inappropriateness of the situation(she also mentioned that she didn't suck him cos she thought it was sick). My son also, later(and quite regretfully and tear-faced), confessed about the whole scenario to me, worried about his sister. My wife still doesn't know about this incident.
For 2 years after that incident, my daughter would blackmail my son on everything(from choosing her TV channel, to playing a game on the computer), threatening him that she would tell about this to her mother. But now, she doesn't mention that incident at all(she is 10 now). Could she have forgotten it, or just doesn't want to mention it? Would this have had a bad impact on her?
PS: My son and I are extremely close, and can discuss about any issue. So, if there is anything my son needs to do or I need to tell him, please tell me that too.

[Harv_c]

Since you discovered how much your son knew about sex, I hope you had the complete sex discussion with him to include the respect that he needs to have.
Your daughter has not forgotten.  She will never forget.  She is just choosing to not use it.  
The bad impact would be she learned early how to manipulate others using sexual implications.  
The bad impact on your son is he learned to not share everything with close family members, namely his mother.  
I will not go into those relationships here, but if you want to discuss these, message me.

[AnnieBrooke]

Are these kids siblings or step-siblings?  Did you have your son apologize to his sister?  Why did you let her get away with the blackmail?  Probably she doesn't want to mention it because the whole thing is embarrassing to her.

[aryanpandeyim]

They are siblings. Ours is a very happy, open and family, and has been for the past few generations, free from any hangups or controversies.
My son DID apologize to her and to me. He was genuinely sad. The love between my kids is extremely good, better than between most siblings, so any form of rivalry between them is of a small scale and short-lasting. Their quarrels are only over little things, like the remote or I-pad.
Also, my daughter doesn't know what the hell my son was up to, and she doesn't even know it's supposed to be wrong. That's what I'm scared about.