"If you think so..." Rach answered uncertainly, sitting down next to the creek. Ty stood up, stopping stroking his cock for a moment, and inspected the water.
"Tell you what," he suggested. "How about we both drink the water at the same time?"
"I guess we could," Rach replied. The two of them got on all fours before the creek, put their mouths to the water and slurped it down in unison. It tasted just fine, and they found it was pretty moreish, both of them leaning down again to sip at it more.
Looking up, Ty smirked, "I guess it was fine." But they could both feel it wasn't. Drinking from that stream had inflamed their horniness even more. Ty's cock started to almost ache with need to be jacked off, and he noticed Rach's body getting turned on, the scent of her moistening pussy coming from between her legs while her nipples perked up.
Drinking the water had made breeding feel less like a command from the beasts, and more like an instinctive desire. "Ty?" Rach mumbled, her head fuzzy.
"Yeah?" Ty replied.
"I want to be pregnant now," Rach breathed.
Ty leaned forward and kissed Rach, and she eagerly kissed back, his hands playing with her breasts as hers reached to stroke his insatiably hard shaft. Rach lay back and spread her legs, and within seconds Ty's cock had pushed inside her. Ty started railing her as forcefully and eagerly as a beast, neither of them able or wanting to stop. Everything had been blotted from their minds besides the thought of breeding, and making each other's bodies feel good.
But once they were both on the cusp of cumming, more changes caused by the water started to affect them...