Ugh help

I get off to lesbian porn. Often.

Do I tell my fiancé? I’ve never been with a girl in any type of sexual way and sometimes I think I want to but then I really think about it and change my mind.

I feel wrong keeping this secret from him. He doesn’t know I watch porn at all

Edit: neither of us watched porn for majority of our relationship until now. We didn’t agree not to but mutually didn’t