There is a connotation joke that I have never understood. Please give me some advice.

Xiaowen crossed her legs before she had a boyfriend. After he got a boyfriend, his legs parted and he became a sixth grader. Before a man found a woman, Xiao JJ was still young, so he was called Xiao Tai. After inserting Xiaowen, Xiao JJ straightened up and became A Mu. I went to Thailand for surgery, cut off my penis and became a shemale (Thai shemale is famous).