Ruth Sadelle Alderson

If you don't know what knotting is, fanlore has a good overview. I'm sure there are a lot of interesting stories to tell about alpha/beta/omega worlds, but I'm not in it for those stories. I'm totally in it for the porn. Overstimulation/people taking it beyond what they think they can is one of my top five kinks to read, and knotting totally plays in to that. These recs tend toward the shorter and plotless side.

SPN RPF

Working Hard/Hardly Working by poor_choices. Chash has done a fair number of knotting stories around the question of "What about the girls?" and this is my favorite of them all: Jared Padalecki/Danneel Harris/Genevieve Cortese, "Jared has the best job ever, in that he gets to fuck hot omegas and make out with a hot beta during his downtime." Bisexual threesome; what more do you want?

There's a jangle of bells, and Danneel sighs. "Customer," she says, slumping back against him. "What do you think, yours or mine?"

"I hope mine," he says. "I've got a raging hard-on and you're not available until eleven."

"Longer, if this girl wants a proper knotting," Danneel says, smugly. Jared isn't allowed to get off with Danneel during work hours, because he needs to be ready to take care of the omegas if they stop by. Which works for him--he just follows Danneel home and fucks her on her own bed.

Sure to Lure Someone Bad and its sequel, You Are A Fever by Obstinatrix, mistyzeo Jensen Ackles/Jared Padalecki, "Jensen plans to take care of his heat the way he normally does: alone. But there’s a stranger on the subway that has a better idea."

“I’m Jared,” the guys says, very quietly. “And I’m gonna fuck you.”

It should be insulting. It should be ridiculous, and outrageous, and the exact opposite of really goddamn hot, but it isn’t. Jensen sucks in a sharp breath, a pulse of want and need rocketing though him. His cock is fully hard now, throbbing in his jeans, and he has his briefcase positioned just right to not scandalize the whole train. Jared takes another step into his space, gets a foot between Jensen’s boots where he’s bracing against the subway’s movement, and his hard thigh between Jensen’s spread legs. His crotch is against Jensen’s ass, and Jensen can feel the solid line of his dick.

“Jensen,” Jensen says, choking on a moan as the guy, Jared, ducks his head to the curve of his neck and inhales. He’s obviously got his animal instinct in check, just enough that he can keep up the charade of normality in public, but Jensen’s got a feeling this guy will take him apart.

X-Men: First Class

Reading XMFC fic usually just makes me irritated with the movie all over again, but we're just in it for the porn here, so the plot doesn't really matter. (This is also why the not quite 60s elements of the porn don't bother me much.)

Fighting Acceptance by heeroluva Hank/Alex, "Not all of Hank's changes are so obvious, and he has problems adjusting. Alex finally gets through to him."

Alex’s mind abruptly supplied him with a vivid image of what it would look and feel like fully erect, but Alex pushed it aside. Mouth suddenly parched, Alex swallowed thickly, his tongue darting out in a failed attempt to wet his dry lips. Forcing his gaze upward, Alex met Hank’s terrified, wide-eyed gaze. He was obliviously prepared for rejection, for disgust or fear.

Those were the things farthest from his mind at that moment, and probably one of the hottest things he’d ever seen. Alex said as much. “You’re hot.”

much in common by 1001cranes Hank/Alex, "Kink meme fill. Knotting, and neither Alex nor Hank know what's coming."

Hank catches him staring, and that's it, the awkward-face is back.

"Don't even," Alex says, and he launches himself at Hank for good measure. Literally launches, and he knocks Hank onto the bed more by surprise than force. "I can't wait," he slurs, because sex does this to him, it knocks him out, it makes him languid, it makes him want. He gets pushy and malleable all at once. "I want to suck your cock so bad," he croons, shoving one hand between Hank's legs, fingers sliding just over the head, and Hank makes a noise like he's been shot.