depends on who it is.

My MIL is also a massive snoop. But I would let her...only because I'd rile her up by placing incredibly inappropriate and offensive (to her) items around the place

My Step Mother is also a snoop. I'd let her house by putting electronic booby traps around to scare the cadoodle out of her!

My sister is a shocking snoop. The only way she would be left alone in my house is with a pitbull guarding every room she wasn't allowed in...and that's AFTER I locked all things I didn't want her seeing/touching in a secure safe...1,000Km away!