She persuades him

"He may not be up to our standards now, but I think I can change him... Just hold him back for me." You grab Justin from behind and cover his mouth as Helen gets to work. She shreds his clothes with her claws, taking her time and kissing and licking all of the exposed skin. Justin tries to fight back but with all the pheromones in the air, your boobs pressing against his back and his girlfriend, reborn as a succubus, caressing him, he can't stop getting hard again. "Aww... You have such a nice cock that I just have to taste it..." Helen teases him and slowly moves her tongue around his dick, giving it long licks.

Justin struggles harder in your embrace but you can feel his resistance melting away. "I bet you didn't think your girlfriend would give head in a church." You tease him as Helen begins to suck his cock, her head bobbing up and down. "She's a nasty little slut isn't she. Justin tries to scream but you can easily muffle his sounds. "Oh no no no... You won't be warning anyone. With or without your help, everyone in this church is thoroughly fucked. Just as fucked as you are..." Justin is already changing, every time Helen pulls back to suck on the tip of his cock, it has grown a bit longer and thicker. His abs getting stronger. His ass that is pressed hard against your waist is getting better as well and you risk releasing one of your hands to give him a squeeze. Justin moans against your other hand and doesn't seem to realize that he could try to break free now. When you press your fingers against his asshole and slip one in, he shivers. You wink at Helen, it is time.

Justin is suddenly freed and he stumbles as the two succubi stand back. Helen licks the precum and drool from around her mouth and leans back on a box nearby. "So Justin, here's your big chance... You can scream for help and let the others escape... Or you can finally fuck my pussy." Helen spreads her nether lips and swirls her fingers around her cunt, showing how wet and ready she is. "You never got a chance to taste this when I was a mortal, but I can guarantee, it was nothing compared to the perfect succubus pussy you see before you..." Justin is still gasping for breath but is now hypnotized by the sight before him. "Go on boy..." Finally he manages to tear his gaze from the dripping wet cunt before him to look at you. "Just one scream and the people outside this closet will start running. Who knows, some of them might even get away! Hee hee!" Justin's face is red from shame and excitement. "...Or you could join us. All it will cost is your soul, I'll even let your lover be the one to take it." You move behind Helen and start kissing her neck and help her pose for the still-human Justin. "Yesss... You remember how I was a spitter, now I swallow... I swallow cum and souls and lives... Join ussss..."