This happened between my dad and I when I was 15. He is a doctor and said that I needed a check up. Instead of going to another doctor my dad said he would do it, so I went to his office and I was the last one for the day. The first thing that he made me do is to take off all of my clothes. I didn't mind because I am the only one my dad lives with and we go around the house naked a lot. So the last thing that he had to do was things with my penis. After a while of him doing things with it I got an erection.
He told me that he never seen any one my age who is so big before, as I was seven inches and uncut. He told me to lie back, so I did and he went to get something from the cabinet.
He came back with a bottle of lotion and said, 'Can I see you masturbate?'
I said, 'Sure!'
I masturbated and then he took off all of his clothes before lying on the exam table with me. He started to masturbate too and we came at the same time. Then we did each other.
After he said, 'Thank you son.'
I told him it was no problem. Now we masturbate together as often as we can.
He says, 'I have to examine your penis.'
I say, 'Only if I can examine yours.'