I put depends (though now as I am writing this its maybe more a no), anyway.
My mom/sister/myself do talk about sex from time to time (though usually its more uncomfortable than informative as my sister is... how do you say more on the naive side of sex). Often jokes/comments are made that usually are said in a more judgmental tone (even if not intended to be judgmental) or even naive/stubborn/ignoran t tone so I try to stay away from open conversations now after many of the things I enjoy being placed in a dark/wrong/misundersto od/etc light.
One of my cousin's and I on the other hand are both as open as family can be with each other about sex/sexual experiences/etc. Thankfully I also have some great friends who are open to hearing or discussing the holes in conversation with family (not to mention a fantastic non-judgmental/open boyfriend).