In theory, yeah it's possible that after all that he/she didn't give it to her/him but reality doesn't work that way and the most probable thing is that he/she probably did give it to him/her.
Do what @jazlovestoskate suggested and take a test to find out :)
no, you will have given it to your partner, just because they might not show signs of it doesnt mean they dont have it. he/she needs to get tested at the doctors to find out
I don't think that, that is possible, I think he should have them by now.