AIO for thinking about getting a paternity test

My wife (40 f) and I (39 m) have 3 kids (10 m, 6 f, 3 m). We live near my family, including my brother, Steven, (42 m) and his family.

This morning my wife and I were going about our normal morning routine and chatting about our kids. My wife mentioned that our oldest son (10 m) was acting a little absent minded and doing a poor job planning. My wife said in reference to our (10 m) "he really is Steven's son".

My brother is often absent minded and we often comment on how bad of a planner he can be. So I am pretty sure she was making that comparison. But that comment really cut deep. I told her that I didn't appreciate that comment and she responded that she "doesn't see what my SIL likes about my brother".

I am left with my head spinning. I don't think my wife would cheat. But part of my brain is saying "get paternity tests just to make sure!"

Am I overreacting for thinking about getting paternity tests for my kids?