A sexual encounter at a family wedding

I (24) went to a cousin's wedding and was unattached and was paired with my aunt (38). We drank a bit too much and next morning I awoke in bed with her and both naked. When she awoke, we had sex again and went our separate ways as they say. Two months later, I was home on break from university and my aunt arrived with her husband (60) and announced that she was pregnant. He hadn't thought they would have any children but said they had gotten lucky as he had a very low sperm count. But he said it only takes one to do the job. My aunt got me alone and said it was me who got her pregnant, asked me not to say anything, I agreed to keep our secret. That was 7 years ago, and I now work for my uncle who is very happy with his daughter. I'm dating women and no one special yet, but my aunt makes sure I get drained regularly. She likes to keep it in the family.