Her crotch lands on top of his (Vaginal, through panties)

Shana was not wearing good underwear that day - they were clean, yes, but they were also an older pair, and as such were not ‘structurally sound’. At the exact time of the fall, Nick was still also completely erect, his throbbing, hard member being completely exposed. The moment Shana fell on top of him, there was a tough resistance in her groin. Her panties were pushed to the breaking point as Nick’s member went straight for her feminine flower like a heat-seeking missile. The thin layer of fabric between them proved to be no obstacle either way, as due to the angle and **** of Shana’s fall, his rock-hard cock broke straight through!

Shana collapsed on top of Nick, stopping herself from headbutting him as her whole body tensed up. The two of them lay there, frozen, inches away from each other and joined at the hip.

Somehow, by some miracle, Nick had managed to fully penetrate Shana, down to the hilt, tearing a hole through her underwear in the process. Normally, taking a cock this deep so suddenly would've been an incredibly difficult task for Shana, but due to gravity combined with their momentum, it was completely inside of her quivering pussy.