Sentence:  Ragan began to move more slowly once he was in, but soon he was moving quickly, pounding his balls against Donovan's ass, unable to hold back, reaching his <WSD>sweet spot</WSD> over and over again until Donovan couldn't keep the screams from coming from his throat. 
Meaning of the word marked with <WSD> tags:  The clitoris, prostate gland, or other center of sexual pleasure.