My 'friend' and X

Okay, so here it is, I have this 'friend' and we've been off and on for 5 years. We never really worked out if we liked eachother, because well, she's just to weird for me sometimes, and sometimes i cant be with out her, its confussing...well anyway...my friends friend, lets call her X, is my friend and I see her during my spares at school. I might have told X some things that my other friend has been saying about her to people, but I CANT REMEMBER, i cant remember if it was a lot of stuff or some bad stuff, but i think X took it seriously and then fully had a fight with my other friend, so now my friend thinks that i told X all this stuff about how she back stabs her and everything......I feel so scared that if X tells my friend what ive been saying...but then i dont even no what i have been saying!! i dont think its serious, but i wish i hadnt said anything at all....

how do i react around my friend and what do i tell X???

Well don't lie to your friend it's best to get it all out into the open if it's brought up, just be like "I didn't think X would say anything and I'm sorry that I opened my mouth" and take it from there. And just tell X that if you did say anything not to repeat it. That's about all you can do.