Thanks for stopping by and sharing.
Personally, I wouldn't over react at any particular set of words/terms. I can definitely see where the "only one" phrase you mention could APPEAR scary.
But I suspect this is likely nothing more than cultural word usage. Meaning that it's likely that the particular words should NOT be taken literally. More likely common slang. Like "You're the one baby". I've heard that type of stuff tossed around like loose popcorn
Shrug it off, but like others have mentioned - use it as a trigger to open some more in-depth conversations about your views on the lifestyle, how it unfolds etc. It can make things better - and smoother - for you in the future.