[经济金融] How to talk to sons

Hi I'm Gina.
" X0 h! O, X  I6 B7 ~I'm mother of two wonderful 10 years sons. Their father has left us 8 years ago. ; b% v# d, l" o# a  J
I have a question, maybe some of you can help me?
) F+ o; p3 h" cAt what age should a parent teach their son about ‘sex’ if there is no father around or would it be better for the kid to have a male family member to do this? 1 n9 C& Y2 x/ d$ i9 g) m! d; [
It really bothers me because i've found adult magazine in their room today. ( B# [. O! u) L" |4 H" B* ?
Should I talk to them by miself or ask my brother to do it? # H9 H5 ?3 E' r, f$ Y' G3 O; v: e

4 f0 U8 K; P8 ~) F+ EHope someone had the same problem and can advise me anything.
+ Z7 r2 j: T1 i9 ^By the way, here is the photo of my sons:
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Happy mother of two great sons...