It doesn't quite start to die off until Sybil looks like she's nine months pregnant and due to drop at any second. There's no space for her leg to be bent up anymore, so he lets it go--but even though she's comfortably stretched to her limit, he forces in just a quarter inch deeper to assure that a drop won't be lost. Soaking in its own cum, his tentacle eases up a little on its movement to sway gently in the thick fluid distending Sybil's belly as it finishes off the last few bursts...and despite the quantity of it all, it makes her body significantly buoyant in the water.

From out of the water, Boxer reaches out with a wet hand and places it on her extremely swollen belly, giving it affectionate and approving strokes as he sucks on her limp dick some more.