Professional ethics as romantic obstacle
The bodyguard's professional ethics are not simply a rule that delays the romance — they are the reason the eventual breach means something. A bodyguard who quickly abandons professional standards is a bodyguard whose ethics were never real, which means the reader cannot believe in them as a character. Writing the professional ethics requires understanding why the bodyguard holds them: the specific reasons a protection professional does not act on feelings for a client, the particular risks involved, the professional identity that is at stake. These ethics should be visible in behavior throughout the novel — in what the bodyguard does not say, the line they will not cross, the moment they redirect their attention back to the job. The discipline that is genuinely costly is the discipline that makes the eventual breach feel earned.