As others have shown you racialist is a word, it has been around for hundreds of years, I don't know your mate Ali but he is talking faeces, that is a word too that means poo, and you should tell him so, he's taking you for a squirrel muncher who will believe him when he says he has invented words, also mentalist is a word used to describe someone like Derren Brown who does mind games magic, maybe your friend Partridge used it in a different sense, but it is still a word, they are both treating you like a rusty cardigan if they say they made them up themselves, sorry no offence, also no-one said you were gay, methinks the lady does protest too much, PS I am not really saying you are lady it is just a thing people say no offence.
I obviously stand corrected. I thought the proper word was racist and racialist was used by people incorrectly trying to say racist, it just didn't sound right but obviously I'm wrong. Obviously I am wrong with mentalist as well. As for I'm not gay comment. I was taking the piss out of you.