How did I get an std? I recently found out and got treated for gonorrhea, my question is how did I get it. I have been with one partner in the last 3 years I have never cheated, and he says he did not cheat. He was tested twice, once when I got tested and

Gonorrhea. Posiitve gonorrhea tests are very accurate, so for sure you were infected. But the tests miss some cases; must asssume your partner has it, even with negative tests. In 99% of situaitons like yours, one partner or the other has had other partners recently. (Sorry that's not what you hoped to hear.) He needs treatment despite negative test results, and both need tests for HIV, syphilis, chlamydia.
Sometimes, . Sometimes, after ruling out the usual suspects, we are left with an unsolved mystery. If you have been treated with a negative test of cure; and your contacts have been checked this is probably the best that can be hoped for.