There are several things you never want to do or say to an Italian. If you would like to avoid pissing them off, then please be sure to refrain from doing the following 10 things.
1. Walk through their house with your shoes on.

Most Italians do not like guests to walk through their home with their shoes on. Even if they tell you that you can leave them on, just take them off out of respect.
2. Put ice cubes in your wine.

Putting ice cubes in wine is one way to make an Italian cringe. Doing so makes the wine lose its flavor. There are plenty of other ways to chill wine such as putting the bottle in a bucket of ice. Other drinks such as Aperol spritz are an exception to this rule.
3. Serve them overcooked pasta.

If you’re ever cooking an Italian pasta make sure you cook it for 2 minutes less than then the directions call for. Overcooked pasta is
non buono.
4. Ask them if their family is in the mafia.

Many Italians hate mafia stereotypes. So if you have a new Italian friend, please don’t ask if their grandfather knew Al Capone.
5. Use their bright white decorative bathroom towels.

These are strictly for decoration. Trust us on this one.
6. Talk about your love for pineapple pizza.

In Italy, pineapple pizza is just about as weird as eating chocolate on lunch meat. It is in no way considered Italian food. Typical Italian pizza toppings include Buretta, prosciutto, eggplant, and Tuscan sausage.
7. Equate Nothern Italy with Southern Italy.

If you consider someone from Calabria to be exactly like someone from Piemonte you’re incorrect. Sure both individuals are Italian, but their culture and traditions are not identical. Each province of Italy differs economically and people in different parts of Italy even have physical characteristics that differ. For example, in the North blue eyes and lighter hair are more common than in the South.
8. Pronounce Italian food names incorrectly.

Before you call Gnocchi “Gah- No- Chi” please think again. Doing so may make an Italian’s ears bleed. Not really. Actually, maybe.
9. Tell them to lower their voice or calm down.

If you’re truly trying to help an Italian to calm down the worst thing you can possibly do is say “calm down”. This is especially true for Italian women. It is never nice to be told to calm down or lower your voice when you’re upset. This is usually counterproductive.
10. Tell them that all pasta types are the same.

Each pasta is made for a different type of sugo. So don’t tell an Italian that farfalle and rigatoni are the same things because they will definitely debate it with you.

Sources:
Everything absolutely correct but the point ONE!
There are very few Italians who wants you to take off your shoes… I may say less than 10%. We simply don’t use it! Only the owners of the house do it for a matter of comfort…
…believe me!
In my house you take your shoes off unless you want a wooden spoon across your head.
You never, ever put your feet on the furniture with your shoes on! A smack on the back of the head is sure to happen for doing that. It’s considered to be dis respectful.
Gabrielle is right, and I am 100% Italian
Quite correct! It is rude and unexpected to remove your shoes or walk around barefoot inside anyone’s home – not even your own!!
Having pizza with pepperoni is just as bad as asking for pineapple, but at least they might give you a bell pepper pizza in between you making this mistake and them getting angry when you figure out some equivalent spicy salami and start asking them to make “That’s-NOT-a-pizza!”. (This is why I laugh at American pizza joints who act like both Canadian Bacon *and* Pineapple are an affront to their Italian heritage, but half their “by-the-slice” pies in their case have pepperoni on them)
Sorry…but she forgot, “Pronounce it EYE-talian”
I think I might be Italian. lol
I once read a satirical food article by a retired USMC mess cook which concluded,
“You call it pasta, I call it 24 kinds of noodles, with 2 kinds of sauce.”
Two of my biggest pet peeves are: Eye talian and do you have relatives in the mafia. My reply to Eye talian is “my parents are not from Eyetaly and the mafia one. Wouldn’t you like to know!!
EYE- TALIAN IS AN OPTOMETRIST, OPTICIAN, OR AN OPHTHALMOLOGIST FROM EYETALY.
All good except for n 1. No Italian will expect you to take off shoes. We hate go bare feet in the house (we can catch a cold..)
all good except for point 1 – never seen or heard of this. more likely don’t EVER put your feet up in an italian house, it’s the pinnacle of disrespect
Tutto giusto aparte il primo, non devi toglierti le scarpe, ma e sempre meglio chiedere.
everything is correct
apart the first one, you don’t t have to but it is always better to ask.
Pronouncing your own name incorrectly. For example dropping the “e” at the end or incorrectly pronouncing “ci/ce” “chi/che” “gli/gn” in one’s own name.