Don't Get on the Bus - S4.E21

The mayor prepares for a three-day trip across New York on his new campaign bus. Paul and James grow mustaches when they think that Carter's gets him the best assignments. Nikki becomes a female version of Stuart when she consults him for dating advice. After Mike discovers that Trevor has asked Caitlin to marry him again, he accidentally hits him with the bus. Mike and Caitlin kiss but their session is interrupted when Mike reveals he was deliberately aiming for Trevor.