It's not a matter of trust only. This place has mental effects from its magic, or so I've heard, so you might be compelled or have your mind read. And there are things he can't know.

[ ...It's a little funny how he hasn't, and wouldn't, throw Wukong completely under the bus. Knowing how devastated MK would be if he knew that Wukong killed Macaque keeps him from even entertaining the idea. ]

Do you need someone to talk, or is being in the same place enough to give you the benefit?