Addictive personality

So, my SO of 10 years and father of my child, has a pinched nerve in his lower back. We all know how this feels, it sucks. Well, for the past 3 days he’s been getting tramadol from his mom which is an opioid. Let me note that me and him are completely against pills and we usually don’t even take them for a headache if we can make it go away on our own. 1 st day I didn’t think twice but it’s the 3 rd day of him taking these. He has a very very addictive personality. He won’t even drink alcohol because alcoholism runs in his family. My mother has been addicted to pain pills for 15 years now and it’s the worst ever. I’m just scared he’s going to become addicted, scared it’s going to start off as “ oh it’s not a problem” to becoming a casual thing. I just dealt with it the majority of my life and don’t think I could deal with it again. I guess I’m just venting but still slightly worried.