A sick TV show, where bikers giver, get er done and pull of some amazing trials, urban, downhill and freestyle riding.
<man> you dude, did you watch Drop In last night?
<dude> yea man it was sick.
to literally drop in on a woman when she is bent over during sex; a combination of doggystyle and the jackhammer; where the male goes up and down in a vertical motion
"oh yeah dude, im going to drop in on that for sure."
"She fucking loved it when i dropped in"