Think I have crossed a bad line!!! HELP!

Hi all! I have a moral dilemma and I'm not sure if I've done the wrong thing! 2 nights ago I hooked up with my Step-cousin. I know we're not blood related, but I feel like I've crossed a pretty big line. Our families aren't actually close as in we have seperate parties for our married grandparents,  but I feel like both sides of the family will be disappointed if they find out. Thoughts? Just in case this sounds too weird to be an adult- I'm 25 haha