“hi i was the one who asked “so i have this friend who i think im falling for, but hes younger than me not by alot….” you told me to go for it but i think its too late hes interested in my sister and i know she like shim too. what do i do now?”
This sounds a bit messy. You do realise there are shit loads of other men out there? You don’t need to chase just this one? If he likes your sister, there isn’t much you can do about it. I’d let them get on with it together and move on to the next dude. God knows, there’ll be so many more, I promise!