Though Tyson has absolutely no poker face when it comes to his emotions, it can be difficult to follow what he’s thinking from his face; as he ricochets from one thought to another at a breakneck pace.
His hands, however, are more consistent and slower to react. A lot of his tells and nervous ticks can be observed in Tyson’s hands. The ring finger of Tyson’s left hand twitches when he’s lying, as Sebastian once broke it after Tyson lied to him, but that twitch doesn’t account for Tyson telling half-truths or teasing.
It simply happens, and - because of that tick - Tyson can easily be mistaken as lying by those who recognise the tick for what it is. Because of that, and all of his other nervous twitches, Tyson is very conscious of what he is doing with his hands and noticing one of his nervous ticks can snowball into Tyson becoming even more nervous.
Dropping into parade rest can be a comfortable fall back that Tyson feels more confident in, or it can be a deliberate decision to conceal the movements on his traitorous hands.
