Applying/Reneging If Firms Are Close to Each Other?

Was wondering if I can get some advice on my particular situation: it seems that people across WSO in general are okay with reneging as long as you do it discreetly and respectfully, but most of the posts I have seen have been pretty large firms or across industries that don't really care if they lose an analyst or two. I currently signed an offer with a smaller investment firm for next summer, but one of my dream investment firms just opened up an app for Summer 2024 as well, and it's going to haunt me if I don't try applying. However, I know for a fact that these two firms are close (operate in same industry, same types of investments, and worked with each other in past deals), and I'm scared that even if I am discreet about my application, somehow something will go wrong and I'll lose both offers. I'm wondering the chance of this happening, and the chance of people across close firms just casually talking about summer interns reneging? 

Also, I know it's definitely too early to even talk about reneging as I literally haven't applied yet, but I'm scared even the application will be too much and just thought about including the consequences of reneging in my decision as to whether to apply or not.