I answered this in your other post from July - https://www.medhelp.org/posts/Herpes/Performing-oral-sex-on-herpes-positive-people/show/3065409
If by safe, you mean you will not get herpes, then no. It is still possible to get herpes from someone who has herpes eve if they haven't had an outbreak for years. The likelihood of this depends on which type they have, and if they don't know, they should test. A simple type specific IgG blood test can tell them.