how do i tell chinese ppl to stop smacking their mouth while eating?

Spoiler for help:

okay, i know its cultural thing and stuff



but forfcuksake, why do they keep doing THEIR COUNTRY'S culture and common sense in ANOTHER COUNTRY. they are visitor here, why cant they jsut adapt to western culture and common sense? or its just because they are alot of their kind so they feel like its their home and its okay to not try to adapt?



im in UK (manchester) btw, so irritating, a lot of chinese friends in my college but i will definitely offend them if i tell them "dude, adapt, stop eating like horse here"



i know im not the only one thinking like this, a lot of my friend think like this too when i asked them



sry if some of chinese here are offended but please mind my words here ESPECIALLY if you were chinese living overseas so you wont disturb other ppl anymore when eating



thx

desperately need help, its too annoying...

how do i tell chinese ppl to stop smacking their mouth while eating?