How do I get back the married girl who was really attracted to me and so was I?

I am a unmarried male who is 28 now..and a few months back I used to talk to a girl whom I knew from my school days (one year younger than me and who had a crush on me during the school days).To be precise,she's married now and we started talking on facebook chats and later on whatsapp when I sent her a friend request there and she accepted.Thoroughly,I didnt knock her at beginning as I knew she's married and I wasn't interested in this kind of relationship.

However,after a month I knocked her and after the hi and hellos she often used to ask me randomly on chats that why did I add her ?On what level do I see her as a friend ? On what ways does she interest me?

I understood she wanted to know what my motive was and I felt like she's interested as well but I never gave the answer of the question she wanted to hear.I wanted to tease a bit. Nonetheless,she used to talk to me like she's interested and whenever she got the chance when her husband wasn't home she knocked me..and told me never to knock her first.She will do that and she always did that.Anyway,after all the fizz and fuzz one day I felt like asking her something horny and that's where it all went wrong. She was like,'you shouldn't have asked me something so creepy and sexual...and bla bla.' I apologized for that but from that moment onwards our conversations were all dull and little.Consequently,after sometime I realized that she isn't that interested to talk to me anymore and we stopped there.

Now my question..I do realized that I made a mistake but her sexual need wont be the factor for my mistake as all her signs pointed out that she was interested on a extra-marital affair with me.Therefore,why did this thing turned her off and HOW do I get her back now. Btw,she's a VIRGO and I do believe in zodiac signs...mostly. I need your advices.Thanks !