Sex hellllp?

I've been with my boyfriend for 2 years and I've totally been into just guys my whole life however when I started watching porn years ago I've always been into lesbian porn rather than hetero. Never really thought about it until now. I've really been getting more and more turned on by the thought of lesbian porn and even wish I could try it. Idk what to do because sex with my boyfriend doesn't even feel the same. I've asked him if I can experiment and he's not really for the idea because he's afraid I'm gonna enjoy it more than sex with him, and I'm afraid I'll agree :/ Any thoughts ? Hellllppp?!