Londo is riding on the back of a tiger. He knows how dangerous it is and wants to get off, but if he does the tiger will eat him. He has no choice but to hold on for dear life.
The scene with Lennier and Vir is PRICELESS. They are more alike than not at this point...aides who can see everything that's going on, but are powerless to do anything about it. This is clearly not their first such meeting, and it won't be their last. Also: This is another huge WHAM episode. Keep your eyes on it.
04:04 - Londo's expression says he wants to talk. Probably tell everything but he can't! He's in too deep now and the whole situation out of his control. ☹
It makes sci-fi more believable when humans acknowledge there are other species that have physical attributes (here better resistance to G-Forces) than we do.