Re: is oral sex safe?
Will you? No one knows.
Is it possible to be exposed to the virus (HPV) which can lead to cancer while giving or receiving oral sex, absolutely.
Is it possible to get oral cancer from HPV, yes.
How can you protect yourself from getting HPV? Don't have sexual contact with anyone.
How can you reduce your exposure to HPV, aside from complete abstinence? Stay in a long term, mutually monogamous relationship. Live a healthy lifestyle: don't smoke, drink minimal alcohol, eat healthy foods, get plenty of exercise and rest, stay hydrated, learn to handle stress. Many people claim that various nutritional supplements and other treatments can help your body fight the negative effects of HPV. The only one I know for certain that can help is folic acid.
I don't understand your comment about "ie in 3 years time".