Chapuys is such a little weasel. Although he pretends to be sticking up for More due to their mutual devotion to Catholicism, he's actually as politically manipulative as "Tricky" Thomas Cromwell.
Like Cromwell, Chapuys has no sense of political decorum. The dude's not really a representative of the Church, after all—he's a Spanish ambassador. In this light, his constant courting of More (especially his suggestion that they spur on a rebellion in Northern England) takes on completely different connotations. For his part, More sees through these ambitions and promptly informs his buddy Norfolk:
MORE: [...] Signor Chapuys tells me he's just made a "tour" of the North Country. He thinks we shall have trouble there. So do I. (2.127)
Interestingly, the original ending of A Man for All Seasons sees Chapuys and Cromwell warmly embracing after More's execution. Sounds like a powerful moment. What's more, it signifies that although Chapuys and Cromwell are on different sides of the conflict, they act in a similarly hypocritical fashion. Bolt would later soften this ending by giving the final monologue to Common Man, but this original ending speaks volumes about Chapuys's shady nature.