HAD post meal with my untouched relative, she wanted me to drink her milk before she urinates

Soon after eating a delicious meal, I was able to get a glass of milk from the young girl relative who is 18 years old but she had not taken her milk. The questions given to me enticed me to perform, I having no knowledge of the taboo delight that was in store for me. I kept on drinking and therefore having a rather heated session.