Getting a strep throat like infection after performing cunnilingus

So 3 or 4 times now after giving oral to a partner two days later I have gotten strep throat line symptoms with white patches on tonsils and sore throat. Every time it’s happened I tested negative for strep and STDs. However an antibiotic clears it up in a couple days. I was prone to tonsillitis as a kid and probably should have gotten them out. When I would give me Ex head as long as I used mouthwash within ten minutes of finishing I was able to avoid getting an infection.

Has anyone had an experience like this? What bacteria is causing it? Really don’t wanna get my tonsils out at my age and I don’t know if they’d even let me