As a QHI I was teaching pilots to become Aircraft Commanders. They were in the LHS "commanding" and I was in the RHS being a "pilot". As we approached the airfield, I purposely went inadvertent IMC to see how the student would cope. He coped well. I, however, got an immediate case of the leans.
So, we're flying round the radar circuit in a Gazelle(so no aids) me fighting the leans, him grinning at me, knowing full well what's happening and asking: "Do you want me to take over?" Me, through gritted teeth: "No, I'm fine".
Joking apart, it was hard work.