[Rivière]

Your friend T sounds similar to myself. In the past I used to be quite blunt and have a very 'foot in mouth' behaviour. Meaning I would speak without thinking of how my words impact others. Learning to recognise when and how it's appropriate to speak can be difficult at times. Everyone is different and we all have different levels of sensitivity, similar to what you mentioned with your friend J.

I understand how difficult it must be, having one friend not knowing what they did wrong and also having an answer that you can't share with them. I agree with Hollie, see if you can try and get both of them to communicate. Your friend T cannot improve in his behaviour and cannot develop better ways of tactfully putting words across if nobody helps him. Right now there's no better teacher than your friend J.

Even if both end up communicating and there's no positive outcome, unfortunately this does happen. Not everybody is going to get along with one another and there are bound to be personality clashes at some point in our lives. I understand this isn't necessarily involving you per se, but it would be good to help remind both your friends of this.

The only thing you can do right now is to support them both and encourage J to communicate with T.