I was thinking about getting a part time job at a coffee bar for the weekends (mostly for fun). I'm a little glad I didn't pursue this because I'd hate to lose my primary job as an engineer just because I wanted to sling some espresso again. I doubt that would happen because...

It's a much different scenario than what is usually talked about with these stories (2x full time vs full time + part time). Still, I wonder if there is (or soon will be) someone who has a part time job and will get fired for it?

Again, I doubt it because I don't think people looking into the scenario would think that's the right outcome. But you never really know I suppose!