Need Sisterly Advice

I need some advice, I've been having thoughts about trying to sleep with my sister.

I remember when we were little, she and a female cousin would would alternate being pinned down and "kissed" by me. I say "kissed" because i was so young I didnt know what it was, I just pressed my lips against theirs. Growing up to middle school we would swim together in our backyard swimming pool. She didnt (and still doesnt) have much of an ass but has nice perky tits that looked amazing in her bikini top. We would play and it would almost end up as a wrestle in the pool. During this, I would wrap my arms and legs around her and tried to slip her bikini off. One time I got one of her straps down to her elbow but she was facing the other way so I couldnt see anything and she quickly fixed her suit. Other than that, the most that happened was me feeling her a few time and she most definitely felt me once or twice but didnt say anything. I used to use her panties, bras and swimsuits to masturbate and almost got caught because I didnt put them back in the same spot.

We have Spring Break coming up even dont they arent the same week, there will be some overlap. I've thought about trying to wrestle like we did in the pool while watching a movie after our parents go to bed. I've also considered getting into her suitcase and cumming on one of her bras for her to find and to see what she'd say. Or while I'm in her suit I could slip a condom in a pocket that I know shed access then check to see if it was there a few days later. If she leaves her phone somewhere, I could try to see if she has any pictures of herself to prove she isnt a goody two shoes.

I need advice because I know it could go one of two ways, a new step in our relationship or causing huge family tension. Welcomed to having conversations in the comments.