SO is this baby his or not...how much of a liar is he?

Ok before i start i NEVER had with my ex well or after or before we dated im not that stupid lol. ok well when i was dating him he told me when he was 15 he got a procedure done so that his *** didn't have semen in it. so he couldn't get me pregnant of we had . i didn't buy that ****, and it didn't madder cause we didn't date long but where still friends ok. he got his new girlfriend pregnant, and hes saying its not his because of that procedure. ITS NOT A VASECTOMY he made that clear, he said it semi permanent for around 8-10 years. and hes 23 now. he said some BS like a C ring, or C clip. SO any help would be great is he lying or is this real?...thanks :D