Discovering stepmommy's nasty anal addiction

In this fantasy stepmom is rather submissive. She protests but ultimately does as told so her stepson keeps her nasty secret. Stepmom admits she's addicted to her special ass-scent mixed with her strong brown smell. stepson catches her fingering & sniffing her stinky asshole. Stepmom denies it at first but then begs him to keep her secret. She'll do anything. stepson wants to watch her play/sniff her asshole. There is asshole play. Stepmom says she doesn't clean her ass intentionally sometimes to achieve a strong smell. Now stepson wants dry anal sex. Stepmom protests & warns him of the consequences of fucking her dirty stinkhole. stepson still wants it & stepmom gives in. She gets on the bed doggystyle & stepson pushes his penis inside stepmom's dry anus. She grits her teeth & clenches her fists. It hurts real bad. She winces in hurt about her burning asshole.