In a relationship but crave being with a female!

Tasha ♉

Ive been in a serious relationship with my boyfriend for 2 years and I've looked at girls yes because I've been bisexual for as long as I can remember. But now I'm having sexual fantasies of women and noticing women I find attractive much much more. I get turned on a lot thinking about sexual things with women and I've never been like this before. I told my boyfriend about my sexual fantasies but he didn't say much about it. I'm not sure what to so about this. I try to ignore it but thats not really working. Maybe I have sexual frustrations idk. What do you think I should do? Should I talk to him more about it? Because the thing is yes I have these craving and fantasies but I am not sure id act upon these things even tho I want to because I feel like its not fair to my boyfriend. Even if he says its okay... Help?