I didn’t no where else to post this & this is 1 of my favourite places, sorry if there is spelling mistakes but here it goes

So my stepson who’s 18 recently got a new gf, HE BROKE OUT THE FRIEND ZONE! Was megga proud his gf also 18 has been around our family from birth her mom & my mrs grown up together & was pregnant at the same time hence she’s like family,

Recently since there “partnership” has commenced she’s been round the house a lot more then useuall sleeping over etc, every time she comes over she’s always asking about me when I’m going to be home, when I do get home she’s the first 1 to great me and give me a hug, asking to see pictures of what I’ve done at work blah blah blah…. Last night she stayed over I got in late as useuall she’s wearing next to nothing soft baggy pj top & booty shorts can just see the crease line at the bottom of her ass, I went to get changed out my work cloths n gone to make a cuppa tea, she’s come into the kitchen to also make a drink, step son & my mrs are upstairs, she’s slid in front of me to the sink and gently wiggled her bum across me, she made her drink while bent over the sink I didnt move cuz I was finishing up some work stuff on my phone wasn’t really paying attention she turned around and said I always new you was big at that point I kind of woke up to what was happening bounced back in shock of what’s just happened, she giggled again and walked off All night & today while I’m at work different situations have been running round my head What should I do about this???? My brain is telling me to say no & stop but my other man brain in my trousers is saying other wise, Please help