I do understand what Bala said but what we say in character is already limited by certain rules. I don't believe we should have additional restrictions.
At the same time, however, I specifically want to quote "these are just words they arent hurtful unless you make them".
People should be allowed to RP what they want within reason and say whatever they want.
At this time, when a sentence his shaped in way that shows a clear intent to hurt, hit or affect the individual from a point of view that has nothing to do with roleplay and playing the game, the player is going to get a warning or punishment. This has been seen in forum and in-game reports.
I believe that if someone tells your character to end his own life more than once and you, as a person, are affected by it, you should ask them to stop in PMs (I personally have no issues with that unless it becomes excessive). If they keep saying it to the same person after the PM request, they should receive a punishment, just like with gross roleplay when despite the consent, it becomes excessive.
This would mean that the consent is implied for and towards all players but when it becomes too much and you are asked to stop, you should stop.