Step Mom Dilemma

My dad recently passed away which was hard on me and my step mom. She's still raising me as my mom bounced when I was 1 and I've got no other family. Since dad's been gone mindy has been doing things she didn't before saying how my dad didn't like it which is fair enough. Mindy is only 28 and was younger than dad she always kept herself in shape for him because he didn't like women "letting themselves go".
With some things it wasn't that noticeable she'd where baggy clothes instead of the tight leggings or jeans with tight top, she'd leave off the makeup which in my opinion she didn't need anyway. But some stuff knocked me back. She's been sunbathing and swimming naked , sleeping naked, walking round in just her panties and even walked in on me jerking off and said it was fine carry on and to let her know if I needed anything. I really don't mind seeing her naked she is hot but I don't know if she's moving towards more because I inherited everything? She was masturbating in the kitchen the other day and I know she knew I was there and she just kept going and even licked her fingers clean after. I'm masturbating twice a day because of her. Really don't know what to do