I've gotten into your shell
Your plastron: sweetly, it parts for me
Your "cold-blooded" heart, I've really caught artfully (Shelly, own ya, Mydas) 
I'm hot to ... thunder right in
Let's glide so ... down to my den
My bed: stonelime shelf in reef there: lover's chateau; hotel 
Your scutes are so cute, can't resist: ensnarling below your shell
I got through ... your keratin 
Your carapace: bony thing; come, I might
And partake of mating, my dear
In spite of the warring boys who sometimes will bite
With their beak on my cheek and my rear 
Here you go, my flipper-tool, so clever, fit in (clever win) (ever, in)
Fuse our reptility; eggs upped in fertility (make a nest) (then go rest) 
Full-moon light: a clue: sons and daughters, slew
Make new crop: from shore, they crawl in
'Cause I've gotten ... your shell, within
(Swim and swim) ('gain, begin)... 
[repeat every 2-4 years for females; every year for males, of course ;) ]
 OS echo line being subbed: ("baby, baby, baby"). "Shelly" = common name among girls; his sweetie's name here. Guess her last name is Mydas, 'cuz whole thing = pun on green sea turtle genus and species: "Chelonia Mydas". ... OK, that sucked. Whatever... :)
Turtles are ectotherms, varying their internal temperature according to the ambient environment, commonly called "cold-blooded". Little metaphoric pun there on her coyness. ;-D
 Yeah, yeah, it's "limestone" that's made from the shells of coral (living animals, unbeknownst to some), but ya got a better, turtle-related match for "to myself"?
 "scutes" - the bony plates that make up the turtle's upper shell (carapace) and lower shell (plastron). They are made of "keratin", a fibrous protein that is also the key component of human hair, nails, and the outer layer of our skin. When metabolized into filaments, as in the turtle's shell, it is among the toughest biological matter known.
Fun fact, that makes sense, really: The male's plastron is concave (curved inward) to accommodate the convex, bulging curve of the female's carapace (back or top). Picture two pieces of a puzzle -- oh, heck, you get the idea ...
 Some species of turtles will fight over a female (much as humans do, heh!). They'll bite for the right, and the sore losers often continue to bite at the winner, who probably isn't feeling much pain by then. ;)
Female green turtles nest by making a rather arduous climb up the beach, as they weigh much more on land than in water: Average adult weight is about 440 lb. (200 kg); the largest known being 870 lb. (395 kg). The process can take about an hour: finding the right spot; digging; then 30-45 minutes of laying an average of 100 - 200 eggs, during which they are in almost a hypnotic trance. Rude humans with flash cameras or flashlights can scare them away, resulting in no nest, and possibly a dead turtle. All lighting is banned during nesting and hatching season in many beachfront areas where turtles nest, for that reason and because the hatchlings instinctively swim toward the brightest light: the full moon on the ocean, or the car wash across the street.
After laying the eggs, Mommy then covers the nest by using the front flippers to push sand over it. This is both for the protection of the eggs from predators, and to attempt to disguise the location of the nest from same, although the turtle-tracks leading from water to nest and from nest to water are quite obvious to a human who sees them before they're obliterated by other foot traffic, rain, wind, etc. Utterly fatigued, the mommies struggle back down the beach, resting along the way, until the first waves crash over them, taking some of the weight off of them, whereupon they swim away far more easily.
This writer has been fortunate enough to have witnessed the entire process, from water's exit to return, several times, including one occasion where two mothers nested about 50 yards/meters from each other, and within about half an hour of each other. Also seen many tracks the next day, even when the nesting was missed. And rescued a couple of hatchlings, one crawling the wrong way (see "lights" above), the other struggling due to a large bite-mark in one rear flipper.
 Green turtles migrate long distances between feeding sites and nesting sites. Some swim more than 1,500 mi (2,500 km) to reach their spawning grounds. Mature turtles often return to the exact beach from which they hatched.
Females usually mate every two to four years. Males, naturally, visit the breeding areas every year, attempting to mate. (200 million years after turtles appeared, humans did, but has anything really changed? heh! ;)