First, I have to get this off my chest:
“Bite me,” he begged and with a lusting snarl Teddy complied. The bruise would be a dark purple for days and he welcomed the mark as he cried out, “Harder.” *groans and melts*

The title is just perfect and you can see how it fits with this bit:
Instantly he saw that Teddy didn’t smile at just any child with that smile. This one was distinctively different from the smile he’d given Victoire’s baby. How could Louis think Teddy would love all children the same? He’d made himself blind with jealousy and now he had clarity. Teddy’s eyes sparkled brighter—as if when his eyes fell on the being in his arms she became the sun. His smile wasn’t just one of pleasure, his lips were moved by some other force—a force so deep it moved him to beam.
*is now quoting whole paragraphs*

Louis, in the original and in this, tries so hard to keep his heart closed off, and just can't do it, and that part at the end, with “I love you too,” he said, and Teddy paused—for the first time in nearly seven years Louis said it without the usual I think or Maybe hastily tacked on at the end. just made my heart melt.

By the end I was wiping away my tears of happiness. This was so beautiful and perfect. Thank you so much, bb!!!!