secret diplomacy

Hello there. Here's a question about secret diplomacy. I wanted to do something a while ago, but didn't because Im not sure if its allowed. Today, I had a bit of the same situation because I was thinking about a truce again, but in the end didn't really wanted it
I would like to know the community opinion. It's a pretty weird situation, but ill try to explain it properly.
If you are in a large player fog game, and I want to make a truce with player ''X''. The problem is; if I make the truce in game chat, ill give away his position to all the players who border me and don't border him.
So that leads to the situation that if I ask to make a truce with him in gamechat, Im really screwing him over if he doessn't want it.
The question: Is it allowed in this situation to PM player ''X'' to ask him if he's OK with me proposing a truce in the game chat?

If you are in a large player fog game, and I want to make a truce with player ''X''. The problem is; if I make the truce in game chat, ill give away his position to all the players who border me and don't border him.
So that leads to the situation that if I ask to make a truce with him in gamechat, Im really screwing him over if he doessn't want it.
The question: Is it allowed in this situation to PM player ''X'' to ask him if he's OK with me proposing a truce in the game chat?