My humble opinion and a possible solutions / decision for your issue is this:
You should always tell your mate the truth and you shouldnt keep secrets from him, even when it comes to your magical practices and your specific path. So, you better tell him the truth about it until its too late. Dishonesty and discretion shouldnt happen in a pure and truthful relationship, this can also lead to arguments, personal offense, bad feelings, and eventually even breaking up.
The reason I have this idea is this (logical explanations will be provided):
You are mates, who love each other and respect each others feelings and personality (including what they do in their life, relevant to your path and your religion / beliefs as well).
Definition of the word love: a profoundly tender, passionate affection for another person ; a person toward whom love is felt; beloved person; sweetheart.
Definition of the word relationship: a connection, association, or involvement ; an emotional or other connection between people.
If you actually love him and care about him, you should be honest with him and fully respect him.
If he loves you back, he will understand you and respect you for who you are, although your path and beliefs might be different, thats a true love after all. As mates you should be able to understand each other and what you do, including religious stuff, paths and beliefs as well. Thats what mates do for each other during being in the relationship. If you really believe you two can be defined as truthful, loving and respecting mates it means that the second side will be able to understand your little difference, even if your paths, religions and beliefs are different.
Honesty, truth and respecting the second side of the relationship are the most important factors that make you mates and build the ideal and healthy relationship between two people who truthfully love each other, without doubts or disrespecting.
In case he does not accept, respect, love and understand you for who you are, what you do and believe in it might mean that he is not the ideal person for you and that youre not having an ideal and healthy relationship, Which means that this person does not worth your love and respect.
He will understand if he really cares about you and fully respects you. Thats basically what happens in the ideal and truthful relationship.
That was my humble and honest opinion, you can take it as an advice. However, you can do what you will and what you think is the correct and the best thing to do in this case.