system
Given the following post, respond as if you're commenting on Reddit:
human
[Game of Thrones] Why couldn't Ned have told Jon's parentage to Catelyn? Did he fear she couldn't be able to keep the secret? How much abuse did Jon suffer from her because she truly thought he was the union of Ned and some other woman?
gpt
Well, Ned never knew Catelyn until their wedding night, and then he went off to war. When he got back he had a secret, a bastard, and an angry wife that was a total stranger.

Could he trust her with that secret? She and her sister (at the time) were very close, what if she let it slip in a letter? What if she *didn't* believe him? What if they have a marital spat and she leaks the information to King Robert, or someone close to him?

Imagine what *Littlefinger* would have done with that information fifteen years ago.

Of course he couldn't tell her, he couldn't tell *anyone.* Ned was the only man who could be trusted with the secret (him and Howland Reed that is) and he knew he was honorable enough to never tell (and felt the same way about Howland). But he never knew that about anyone else. And Howland went off into seclusion after the Rebellion and he seemed to keep quiet about the ordeal, so that just leaves Ned.

If he tells anyone else, he risks ruining the whole situation. The only solution is have Jon join the Night's Watch, because once he speaks the oaths he can never become King or threaten Robert. Proof of that is the *other* Targaryen in the night's watch.