Photos in Files keep opening in Lightroom

Hello everyone, I've been having a problem recently and I was wondering if someon can help me. 
I have my photos in a file in my MacBook Pro however I noticed that when my photo is loading it says Lr and then when it's about to open it opens up in Lightroom and I don't know why. The photos are in a raw format but I still don't understand why it keeps on happening. I'm a photographer and I have to give these photos to my clients and I don't want them to have this same issue. I hope someone can help me get the pictures to open and stay in the files area and not open up on Lightroom