"We had a number of things in common, we came from the same large metropolitan area, and we both wanted to return there after school, so everything was very natural between us. We married soon after graduation, moved back closer to our families, and had three children by the time we were 30. We were both born to lesbians, she to a couple, and me to a single woman."
You see where this is going? Blah blah blah... "I can't help but think 'This is my sister' every time I look at her now...."