Not just yet.

"Wait a second." I can slowly feel my cock stirring again, Jane notices it too and gasps a bit as it pokes up through the gap in her thighs.
"Haven't you had enough for one night?" Jane asks gently, perhaps also a little teasingly.
"Well I thought I had."
"You know what? How about you fill me up one more time, take it slow though, no roughness now, we have all the time in the world."
Happy to hear these words, I say "Damn Jane, you're the best girlfriend a man could want" She flinches a bit at the title, as the realization dawns her-she's my girlfriend. Then she slowly sinks back into my arms.
I'm about to get on top of her, until she surprises me by sitting up, and lowering herself onto me, my cock impaling Jane's pussy for the second time as she rides my meat, slowly. "oooh.... giddy up cowgirl..." I say teasingly. She laughs a little, clearly liking this.
"Steady up.... I think this ride is making me a little horny." She bobs slowly up and down, the water splashing up against her. I sit staring at Jane's ass, god how I love that ass.
The pace quickens, but is still kept relatively slow moving so neither of us tire out. I reach out and press my finger into Jane's clit, as she moans my name.
I run my wet hands over her ass cheeks, massaging them as she groans, the feeling of my cock inside Jane, and knowing just who it is gives me a thrill.
"Urgh, baby, I'm going to cum..." Jane says as my hands run through her now wet hair.
"Good," I tell her, "cum anytime you want Jane baby" I give her one hard thrust. This sends her over the edge, she quietly moans my name, holding her moan for a good long twenty seconds before her vaginal walls contract, causing me to lose it, sending my semen up into her pussy. Jane moans again and leans back into my arms. I whisper to her about how amazing that was, as she smiles softly and drifts to sleep, becoming submerged in the water and leaving my cock buried inside her.
Completely exhausted, I too fall asleep.