Step Daughter

My long term girlfriends grown up daughter (aged24) has just moved in with us after a relationship break up and I’ve been totally obsessed with catching her naked.
I’m always looking up her little skirts trying to catch a glimpse of her underwear.
I steal her worn panties whenever I get the opportunity to sniff her pussy while masturbating.
I’ve started making her a smoothie in the mornings an adding my full cum load into it and sit and watch her drink every drop.
knowing she is drinking my cum drives me wild with excitement.
I can hear her masturbating late at night when she thinks her mum and i are asleep.
I really need to have her.