Is it normal to have this fantasy?

I had this fantasy for a while now that my girlfriend would lock me in a chastity cage, and wear the key on a necklace, and wear some sexy lingerie and a strap-on, and she would lube up her "dick" and masturbate with it in front of me, and that would turn me on so much knowing that I can't touch my own dick when she's playing with her imaginary dick, and then I would let her penetrate my butt with the dildo and after if she wanted me to lick and suck the dildo I would do it with a smile on my face!