So last night I found a fic with Molly having a knot, and from the description I'd thought it would have Caleb being surprised by Molly's knot, but I was disappointed.

I'd like to see Molly and Caleb having their first time together, and Molly forgetting to mention the fact that he has a knot, and possibly goes into a breeding frenzy/mindset when he has sex.

No noncon, watersports/scat, or transphobic slurs please

I'd like to see:
+ Molly with weird genitalia, like ridges, multiple cocks, etc. Up to you (if you decide on multi cocks, I'd love to see him force them into Caleb at the same time, stretching him and making him whine that he can't take it, and needs to cum, but Molly won't let him)
+ Molly humiliating him for squirming on his knot, calling him his slut, etc.
+ Trans Caleb getting extremely wet just getting fingered
+ Perhaps tieflings have ABO dynamics and Molly is an alpha who thinks of Caleb as his omega
+ Molly popping his knot in and out of Caleb until it's too big to remove, but it doesn't stop him from trying.
+ Molly cumming multiple times, fucking like a coyote 😜