Once he swallows you, he regurgitates you in the direction of his choosing with a stun for .25 second. This allows him to immediately land a 2 second 70% slow and an AA for an immediate 2 stacks of Acquired Taste. Stun aside when he regurgitates he spits you out in a location of his choosing allowing him already be in a position that cuts off your escape. This means you must run in a bad direction or run toward Taum to get away. He lands the third stack easily. Depending on your mobility as a champion he can swallow you again to repeat the process or just stun you for 1.5 seconds, get more stacks, and swallow you to repeat the process.
So given that this is the play pattern, what is the player getting endlessly stunned doing wrong?