Gf wants me to have sex with a sex doll

Recently I got my girlfriend a nice little vibrator that we both enjoy to play with during sex but she has now returned the favor and has now bought me a torso tits sex doll toy. We have been together for 3 years we are both very overprotective of eachother and constantly get jealous of things. I could personally never see her wanting me to fuck another pussy even if it’s fake. im getting used to this and the toy should be coming in tomorrow or sooner.she has made me fuck her while looking at a photo of the toy doll and tell her what im going to do to the doll as well as talk about playing with the doll herself as I play with it turns her on extremely .She has told me she is Bisexual but we are so strict on eachother I haven’t seen her look at a women in a sexual or other manner and I was wondering if this is going to lead to potential ffm threesome or if my girlfriend just likes playing with toys?