He does it fairly constantly, not just when he's angry. It's been almost 3 weeks. I'm home visiting family at the moment and my parents are stressing me out refusing to follow my decision to ignore him totally when he shrieks and pay attention to him when he makes a "nicer" communicative noise. I figured he wouldn't understand why he shouldn't do it but would soon realise he didn't get any attention that way. Instead they will ignore me and alternate between "don't do that darling" and shouting at him, he's one FFS he doesn't understand and shouting will surely only encourage him to be louder. It also gives him totally mixed messages.
It's undermining my confidence as a parent cos they're just saying no our way is better when actually I don't think it is. My brother and I were famously very well behaved/quiet when we went out and I think they were just bloody lucky with that. It has made going out with them anywhere really stressful cos every time he screams they are looking round apologising to people and loudly acknowledging that he's loud in a way that's for everyone elses benefit to show we aren't "that sort" who let their kids run wild.
So how can I encourage him not to scream? How can I stop my parents driving me up the wall in the next four weeks?!