Your browser does not support grid, so will not be supported. Hover over your browser version to see if there is a way to enable potential support. Sorry, I am no longer able to justify working on making the layout work on older devices.
@ anon 2's comment, Isourou Tengoku has the same thing happening, girl walks in on her mum getting it on in the same position.. looks rubbish though, like hentai from the early 80s, really badly drawn shit, so dont bother :p