There is an entertaining discussion of relativism about truth on Stephen Law’s blog, with a fascinating and irritating quotation about ’truth’ taken from a ‘psychic’ website, as follows.

I was told that there is no absolute truth. I was told that ‘truth’ is a very personal, subjective thing. Something that is ‘true’ = a perception or a belief that serves us personally.

My guides then explained this, using the law of attraction to illustrate it. They said:
“You know that your beliefs create your reality and that you can create any reality you want by changing your beliefs. If you focus your attention on something and hold it as a belief, whether you like it or not, you will begin to see evidence of it being true, all around you. Therefore, you must only believe things which feel good to you. Truth is that which feels good to you; that which serves you.”
So, according to my guides:
Truth = something you have focused on, something you decided you want to experience = it shows up in your reality.
Untruth = something you reject, something you don’t want to experience = it doesn’t show up in your reality. – from Psychic but Sane.

This is an extreme example of the kind of things you come across in teaching beginners in philosophy, which I mentioned earlier here. The standard reply is that in claiming that truth is relative, or that truth can differ from person to person, you yourself are making a statement which can be denied by others. You say that we can both be right about contradictory propositions. I say that we cannot both be right. According to you, we are both right. Therefore I am right, ergo we cannot both be right.