PPPD-788 Ever since the succubus I summoned possessed my big-breasted sister, we've been having daily incestuous sex with her milking me dry through internal ejaculation

Unable to get a girlfriend, I desperately tried to summon a succubus to lose my virginity. Just as it appeared, my sister barged into my room! The magic circle... had the succubus possessing my sister's body! I passed out and when I came to... both the magic circle and my sister were gone... was it a dream? However, the incubus gradually gained control over my sister's body and started raping her and impregnating her with no regard for incest! What if my sister gets pregnant...