Made my sister kiss me and it was sexually arousing

When I (M) was about 12-13 and my sister was about 7-8, I played games with her and every time I won, I made her kiss me on the cheek. This was sexually arousing to me, and I sometimes used this to jerk off (as it was a new thing at the time for me). My sister told my parents one time after this, and they talked to me about it.

This was like 4 years ago or so now, and now I’m almost 18 and feel really bad about it. I’ve had a tough last year mentally and regretting past mistakes, and this isn’t helping at all.

These interactions haven’t happened since, and my parents and sister have not mentioned it since. I think I’m just worried that my sister still remembers it and it’ll affect our future relationship (which is good at the moment). Any advice? I feel terrible.