Advice!

Blast from the past!
I've been broken up with an ex-fiancé for about 5 years now and I haven't run into him since then. This week I realized his parents just moved in next door. My dilemma is should my now boyfriend of 3 years know about them moving in? We wouldn't go to an uncles house because he lived next door to my exs parents and now that they've moved next door to me out of all places idk what to do. I don't have feelings for my ex anymore but just the thought of running into him when/if he comes to visit his parents is giving me a headache. I don't want my boyfriend to think I'm keeping things from him if I don't tell him and then he finds out. My heart is telling me to tell him but everyone else say to keep it myself unless I want to create an unnecessary problem between us since he doesn't even know what my ex or his parents look like.