When I was in the 7th grade (12.y.o.) there was an 8th grade girl (13.y.o.) who I liked a LOT. I started sitting with her on the school bus. Eventually, I worked up the courage to hold her hand, which she allowed. Then, after about a week of hand holding, she would relax and lay back against me, and I would put my arms around her from behind. After a few days of "bus spooning", my hands started to wander from her hips/waist towards her chest.
After cupping her breasts in the palms of my hands (over the top of her school uniform), she said, "You are a very naughty boy! If you want my breasts, get off the bus at my bus stop and follow me." I followed her instructions. She took me to her family's barn/woodshed. Where she told me, "You can have my breasts now. I will give them to you willingly. But, I punish naughty boys!".
After about 20 minutes of enjoying her amazing bare breasts (she had allowed me to remove her school blouse and bra), I started to run my hand up the inside of one of her legs/calves, under her skirt. She stopped me and pointed to her father's leather razor strop hanging on the wall. She made me get totally naked, fetch a paint stirring stick and the strop, and stand in front of her. She used the paint stick to thoroughly spank my erect penis (which made me have the most explosive tween orgasm when the stick started "punishing" my frenulum area), and then severely tanned my ass with the strop.
Then she said, "Maybe next time I will allow you up my skirt. If so, you should expect even more creative and painful punishments!"