Should I even bother telling her what I saw?

I mostly stay over at my SOs place but decided to head to mine since I had to take care of some stuff early tomorrow. I got home, got everything ready for tomorrow and decided WTH I'll just head back since I was able to get what I needed for tomorrow. When I was pulling up, saw some dude exiting a vehicle and approaching her door. He saw me and tried to conceal his face while at the same time, heading back to his vehicle. It was obvious by his appearance and time, that this was. I pulled around and saw the blinds open with lights on even though she has texted she was going to sleep 30 mins prior. I left and texted her something I unrelated and have yet to receive a reply.

Just to be clear, this isn't a case where I just so happened to stop some guy from breaking in or something.

Should I even bother telling her what I saw?
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