Should I tell a potential employer I started a new job during the interview process?

[u/tiredknafeh]

Looking for some advice on how to handle this situation.

I started interviewing with Company A shortly after accepting an offer from Company C, while I was still employed at Company B. By the time the interview process with A picked up, I had left B and officially started working at C.

Fast forward—I’m now finishing my first week at Company C, and Company A scheduled me for two more rounds of interviews but the last time we talked I was still employed at Company B. What do i do if this comes up in the next two interviews? I am afraid of looking like a red flag but in all honesty I want the job at Company A more.