My boyfriend and i got tested for stds my tests all came back negative his came back positive for syphilis he's saying he got it because we had anal sex without a condom even though all my tests including syphilis came back negative?

Sorry, but your bf is wrong. With your negative syphilis test, it is not possible he caught it from you, anal sex or not. If his test has been positive a long time or not tested previously, maybe he had it before your relationship began. If he has new syphilis, he caught it by sex recently with someone else. In that case, you must be treated, even if your own test is negative. Good luck.

One does not get syphilis from anal sex unless the other person is infected. He should repeat the syphilis test to make sure it is not false positive e.g. do the SpiroTek. If it is positive then he has had contact with a positive person.