I think i want to sleep with my little brother

And he wants to sleep with me. <br><br>Let me explain, he's 18 while i'm 21, we're from the country and he's got friends that would say it's not weird and that they would also date their sisters if they have the chance, he's seen a couple of videos of us when we were kids and wants to recreate those memories, I would like to do it but I would also be doing it because I know how much he wants to do it and I dont want to disappoint him.<br><br>The problem is that our parents are going to be away for a couple of weeks and we're going to be alone so i know what's going to happen... But I feel like if I don't do it I will resent myself for the rest of my life but if I do it and he or I regret it we will have to lie for the rest of our lives, and if our parents ever find out I know he will resent me and me him for it...<br><br>So what I want to ask is how do I know if I should or couldn't do it?