There are a number of possible scenarios. Your boyfriend's childhood "cold sores" may not have been cold sores at all, but chelitis or something similar. Alternatively, he could have HSV-1 and the test he took didn't look for it - I would be interested in the specific one he had done, as some blood tests only test for HSV-2.
If he tested positive for HSV-2, you are susceptible to contracting it if you do not currently have Type 2. I recommend finding out about precautions to take during sexual contact. Is he on suppressive medication?
Yes it is theoretically possible to have both viruses in the same location.
However when in the oral location HSV2 causes cold sores very infrequently, I believe it averages once every few years.
Hence if you're having a run of cold sores, overwhelmingly it will be caused by HSV1.
is it possible to acquire oral hsv-2 on top of oral hsv-1?
even the best blood tests still miss 1 out of every 10 hsv1 infections. odds are your bf has hsv1 orally even though his test results aren't reflecting it. had he confirmed his hsv2 status with more testing? having hsv1 can cause false positives.
can you have frequent hsv1 oral ob's? yes you can but also many other things can cause them. see your provider to get one of these swabbed to be sure it's all a herpes issues and also ask about daily suppressive therapy to reduce the frequency of your cold sores.
This is quite unlikely. Was it an IgG test that produced a firm positive for your boyfriend? He more likely than not has an oral HSV1 infection as well. Your cold sores are more likely to be HSV1 related with your body under stress at present.