Footsteps while looking up/down "inside" players.

While you're effectively "inside" a player on a Multiplayer Server and you look up + down the noises for walking over wood/grass etc play, I have been un-able to find this bug anywhere on the bug tracker.

This happens using Optifine and I also tested on regular Minecraft, no mods installed but this still happens.

Steps to Replicate:-
1) Join a Multiplayer server.
2) Stand "inside" another player.
3) Look up + down.
4) Hear the wonderful sounds.
5) ???
6) Profit...