I am closeted about my kink as I have no idea how my wife would take it.

So this is a bit of a long story but basically, I am 20 years old and I have a 16 year old sister. When we were kids we were always extremely close and we shared a room together until i got my own bedroom at 17 in our house. I would say it was only in the past few months that I started actually developing feelings for her. We are really close to the point where I know everything about her and she knows everything about me. I didn't really start to develop sexual feelings about her until recently, but I realise now that I have been grooming her. When she turned 11 and got her first bra I did have a brief second of wanting to see her, but I didn't dwell on it and trying to look at her as the little sister she was as I didn't want to over sexualise her and I did because she was so much younger than me and she really didn't look much older than when she was 9. Then in the past few months I have been getting a bit more sexual about it. Still not how women but I do look at her in a sexual way. For example, I will look at her and be like wow, she has a nice butt, or her thighs look good. I didn't expect it to go as far as it has without me even realising what I was doing. But now it's gotten to the point where I am worried she will find out. I am going to university next year and I have asked if she could come to the uni party with me and I know that when I am there I am going to act on it and I don't want to do that until she is legal. I am not sure if she feels the same way and I have been pretty subtle about it as I don't want to make her uncomfortable. It's only really gotten more obvious in the past few months when I am on the computer. I will have been on it for hours and if she wants to use it I will just leave it up on porn and make a comment that she can watch if she wants and she normally does it. I have started leaving things more and more obvious up so that she can see but I have also made sure that it is just innocent enough that it isn't sexual harassment. I feel like I have messed up because I have left pics of me fucking my wife up on my phone for her to find. I know this was a bad idea in hindsight.