"H-hey!!" Alison calls out in surprise as you spray her with your seed. She winds up with spurts all over her face, glasses, hair, and some in her mouth. When you're done, she looks up at you in annoyance.
"Jeez, for a demon... -powered shapechanger, you sure are a quick shot," she says, annoyed. "And I haven't even gotten started. You better hope you're still up for it, 'cause you still owe me a fuck, dammit!"
She gets up when you're done cumming, walks up to you, then grabs your still-hard dick. Instantly, you feel as though something has trapped your balls in a grip, not a crushing one, but it feels as though they're unable to spew anymore.
"A special spell I was working on," she smirks. "I was going to try it out when interrogating an incubus - if I ever managed to catch one - but I guess we'll have to try it on you. Basically, you can't cum unless I allow it. You can see why it would work nicely on horny demons - and maybe against you? Let's try it..."
She shoves you onto the bed, and casts another spell. Suddenly, your limbs are forced spreadeagle, as though you've been chained down to the bed. Alison looks down at you lustily.
"I hope you're ready and have a good amount of stamina," she says with a naughty smile, "'cause I haven't had some in a while and am really backed up!"
She straddles you, her hips hanging above your erect penis, ready to impale her leaky pussy on it. She lowers herself a bit, and presses her pussy lips against your glans, letting them rub a bit to tease you.