Well, I am all prepared to meet my Headmaster. I have just been into town to buy a fresh pair of black stockings and panties, a white shirt (size 16, sadly) and grey-pleated skirt.
He is going to take me to his spare bedroom, ask me to display what clothing I have brought, and tell me to get changed into the schholgirl clothing. I will be left alone. Whereupon, I will wash my penis in the bathroom and get changed. Finally, I will put on a short wig to complete the transformation from Sam to Samantha.
Then, I announce that I am ready for whatever follows. I shall be made to sit (for perhaps half an hour) outside the headmaster's office. Hands on knees. Legs apart. This concentrates my mind.
The door to the office will open, and I will be summoned inside.
Each subsequent event always starts this way. My penis is always erect at this point - but he never touches it - preferring to have me on all fours on his bench at hip-height. I am usually given an enema at this point. Memorably, once I made the dreadful mistake of going to him not having evacuated my bowels. I was made to be on all-fours in his bath whilst the enema took effect. Most unpleasant, but the subsequent caning was thoroughly deserved.