Can a Roman Catholic be friends with a Seventh Day Advocist?

I have a new house mate and there have been some nutters living here since I moved in but all of a sudden there is a seventh dayer living in the next room😧😮😳😵‍💫😵‍💫🫨!!!!

Should I be concerned???? They seem really nice and I've already got used to the Atheist who lives here (they are prolly only an Atheist because they do drugs all day and listen to drugs music all day too) and so it shouldn't seem as bad but they believe in some wacky beliefs so I'm scared of talking to them a little because they might start coming out with the crazy stuff.

Should I be worried???