The short answer is yes, but we all have candida on our skin, and usually our immune system keeps it in check, so it is not inevitable that you would get it even if you did give him oral. From another website:
"Thrush, also known as candidiasis, is a yeast infection
caused by the Candida species of fungus. Candida is a common yeast
that is found on the skin and genitals of most people, even those who have not had sex.