Stepdad caught me masturbating

Last week my stepdad walked in on me fucking myself with my hairbrush but what made it worse was that I was coming with my boyfriend at the time.
He was absolutely livid.
Yelling and calling me a little slot, wait till I tell your Mum. He yelled.
She will ground you and take away your phone.
No please Dad I said. As I was trying to cover myself up.
I will do anything Dad just don't tell Mum.
I can't believe what a little slut you are. He said.
Please don't tell Mum I repeated.
There is a little favour you can do for me he said.
It can be our little secret.
OK Dad anything.
Show me the.knickers you had on earlier. I was a bit puzzled but reached down by the side of the bed and picked up my blue lace thong.
Mmm he said. He took them off me and said sluts knickers.
He then really shocked me.
He opened up my still very sticky crotch and held it to his nose and took a deep sniff. Mmmm he said again. So lovely and spicy. He then licked at my fresh girl cream. Really tasty young lady.
I was shocked. Carry on for Daddy he then said.
At the same time he took out his very large rock hard cock and started to stroke while still sniffing my dirty knickers.
Daddy loves the smell and taste of your dirty knickers, they are so wet and sticky. He made me finger myself in front of him, I was surprised at how wet I had become.
He took my fingers out and put them in his mouth and sucked off my cream.
Sit on Daddies face he told me.
I did and he immediately stuck his tongue right I side my pussy.
I instinctively started to suck on his cock and in no time at all we both orgasmed over each others faces.
When we cleared up he said our little secret right.
Yes I nodded. Since then every opportunity he gets he fingers me and then sniffs his fingers.
He has made me give him my dirty panties every day and has made me watch him walk off while he sniffs them.
He told me that he has been sniffing my dirty panties for about 7 years.
He wants me to make a video for him fingering myself and talking dirty to him.
I will happily xxx