M(20), F(19) meeting parents and staying at their house

okay long story short, i'm flying to the uk to go see my 'friend/situationship lol who i was seeing last year. We met in Australia where i live and he was on his gap year, and saw eachother a number of times before he had to go home. Despite not intending to gain feelings for one another it ultimately happened and we left as friends/ exclusive/ non exclusive it's quite confusing anyways 😭 I was given the opportunity to go to the northern hemisphere and since i'll be over there, i'm going to go visit him for the first time since August. While in Australia he stayed in my second house for two weeks, met my family ect, however ultimately we were living separately from my parents. This time, he's invited me to stay at his house however with his parents and im super nervous as this is the first time im meeting them and im also about to spend the next two and a bit weeks with them.

I'm coming to you guys for some advice, what are some tips for meeting the parents? I'm 19 and he is 20, but i want to make a really good first impression and also want to ensure the correct étiqueté while im there. I'm super keen to see him however i really want to make a good impression with his parents given that ill be staying under their roof