Should I contact possible bio dad? 17f

This year my biological mother told me who my biological father is. (Or so she believes he is. She says shes not 100%) I don't know him personally but my biological uncle lives close to him. But he thinks asking for a paternity test is a bad idea because possible bio dad was married at the time, and still is married to her. They have 4 (possibly 5) kids together. I took an ancestry test trying to see if i could find any proof it was him but I had no luck. I'm desperate to know but I don't want to mess up someone's family and possible bio dad is apparently a terrible person anyway. I'm also concerned if he is not my father, the possible issues that could cause. I'm just wondering if anyone has any advice on if its worth it or not?