Shawn was a very curious lad.
The double helix that controlled his growth was unlike anybody before. Perhaps at some time in the future a person like him will be born.
Have you ever made love with a sibling, a twin, or someone you've known literally all your life? Studies suggest that most siblings experiment with sexual play to a degree, and that usually ends when puberty arrives. Some I've known are different, and the bond between them links them together for their lifetime.
A story in the Brennan Universe
Before Bob's birthday, Jeanette asks what he would like within their (small) budget. He asks for her to be his "sex slave" for a day.
Laura who has not been married very long, is having problems with their sex life. After confiding her problems with her next door neighbor, she gets tricked into joining 'The Park Palisades Women's League'. Here she is introduced to drinking and drugs, which eventually leads her to losing her inhibitions and she has sex with another couple, a bunch of dogs and finally her own husband.
Two teen gals get wild with each other. They also have fun with the family dog, and prized breeding horse. One teen gal even has some fun with her male cousin.