I don't receive his text messages?

I am a meteor customer and i don't receive my friends text messages. He is with Vodafone. He receives mine though. I know this is going to sound ridiculous but my ex, his friend, was annoyed that we were hanging out and texting etc. my ex is a computer GENIUS, do u think he did sth so that i cant see the messages?? Reading that, its sounds ridiculous. The simplest answer is usually the right one, but what is the simplest answer????