Monica grows a little distant

I notice it the next weekend. Monica is at my apartment, with no sign of having been recently fucked to exhaustion, as usual. After some playful chat, we start making out.

However, she's quickly gone to my jeans and has pulled them down.

"Oh, you're a little hasty today" I joke.

She stays still for s moment, then looks down at my hardening cock, just let out of my clothes, then she chuckles.

"I just... I'm just in a good mood to suck you. I mean, I'm always in the mood to suck you, just... I..."

"It's OK, go on." I tap her forehead so she can start. Her blowjob is more intense than usual, and she takes my cock much deeper than she used to. However, she looks a little dumbfounded. "What's wrong, babe?"

"I... I don't know." She takes my dick out of her mouth. "I have this weird feeling your cock got... Smaller."

"What?"

"I... I mean, I'm not saying it's small, it's not! You have a lovely cock, and it's big and good, it's just...!" She is really nervous, but she's innocently nervous, like someone who honestly doesn't know what's going on. "I used to be able to fit it all in my mouth, but now I feel I have... Extra space in my mouth. Like... As if you had shrunk."

Oh, god. My cock twitches, but she doesn't notice. She's gotten so used to Marie, and now Jessie, that she's more familiar with a huge cock like her lover's, rather than my average dick. I have no right to get so horny.

"Oh, babe, you've given me tons of blowjobs. You must've gotten so good, it just feels different. I actually feel you're doing it even better than before. There's nothing wrong with either of us." I lie. There's definitely something wrong with both of us. But she believes it.

"Oh... I see. That makes sense."

"Of course it does. Why don't you jump on me and ride this... Lovely, big, and good cock of mine?" I giggle, and she nods.

She gets on me, and I caress her whole body as she sits on my cock and starts riding me. I feel her different here too. She moves much faster and harder than ever. She doesn't look like she wants to be in control, she looks as if she wants to be taken that hard.

"Woah, babe! You're getting wilder!"

She smiles, but she starts to get concentrated on her action. She... She doesn't seem to be enjoying it that much.

"Is there something wrong, babe?"

"No, just... Could you... Do me doggystyle?"

"Sure!"

We change position. Her ass, as usual, looks glorious from behind. I thrust hard from the get go, as she's wanting it.

"Yeah, sweetie, fuck me hard!"

Her hips feel so good in my hands as I pull her towards me, and her pussy is as tight as always. Is she a real succubus? How is it that she hasn't been stretched after getting pounded mercilessly by Marie?

"Harder, sweetie! Please, harder!"

I don't speak for a moment, as I'm thrusting as hard and as fast as I can. But she's demanding more! Marie has definitely spoiled my girlfriend!

"Babe...! Babe, I'm about to...!"

"What? Wait, I need it in my mouth."

She quickly (more than usual) turns around, opens her mouth, and strokes my cock firmly. I imagine her doing that to Marie and Jessie at the same time, and I ejaculate. She expertly catches all my load, a big one, with her mouth. However, after my last shot, she looks flabbergasted again. She swallows quickly, not letting me see her tongue covered in semen, as she usually does.

"That was great, babe."

"It was... Strange..."

"Huh? What, Monica?"

"I mean... I feel you came too little. I remember struggling to swallow your loads and... Today it was so easy. Did you masturbate earlier?"

No, I hadn't. In fact, I hadn't masturbated for a couple of days, just so I could cum in her mouth. And she thinks it's a small load? She must be so used to Marie's huge ejaculations. I feel... Excited.

"Yes, that must've been! Also, you may already feel too familiar with my loads, so..."

"Ah, I see! Yeah!"

"I... You haven't cum, have you, babe?" I hadn't noticed. She always climaxes before me. Always. Now she's also gotten resistant to sex with me?

"I... I haven't. But it's fine!" She hugs me and kisses me. "Why don't we watch a movie? Maybe we can go a second round later."

I'm going crazy. A sensible person would stop this now. No, a sensible person would have never started it. So we need to go all out now.