At that very instant, Sydney falls forward, pulling her pussy off your cock.
You shout: No! You try to thrust forward into her, but you can't. You try to get your arms free, but you can't. You are frantic as your ejaculate drips helplessly out from your cock. You shout and beg her to please stroke you and not ruin your orgasm!
You know from past experience that when your orgasm is ruined and drips out slowly without any stimulation, that it's worse than being denied. It just increases your ache...