Alea, you why are you getting so angry- did you Google Wellness centres in the UK, and found all the links to spas? Why are you making this into a battle?
And yes, a huge sense of humour is needed to learn and teach a language- and students love it, both French to English, English to French, or German and vice-versa. I am so lucky to still have contact with many of my past students- and they always say that it was the laughter and fun, and laughing with each other about mistakes, that encouraged them to continue with languages- as it was so much fun.
'I daren't say it mIss' and I'd say 'go for it- what is the worst that can happen if you get it wrong- we will all have a good laugh together' and it worked and still works - I can assure you. I have absolutely no desire to continue that silly fight with you- it really is your problem if you can't see it- tragic but I will survive, truly. American English, yes- but increasingly used for spas all over UK- and not just for holistic centres- but as said, spas. A shame you keep attacking me all the time- but your problem- but I won't be par-taking.
So, two of my vera talented French students came across the word 'genrE' in a listening comprehension test and didn't understand what was being said. So I explained- and they laughed- and we still do, whenever we come across it, as we do often. And it is just a bit of fun, no more, no less- fun is a huge + when teaching, and no harm at all. My UK students loved to laugh at those funny invented English words that don't exist in English- and that was fine too.
We love to translate expressions word for word both ways. Like 'il pleut des chiens et des chats' or t'other way round 'elle a une frite sur l'épaule'. Fun- just fun- and as said, it works.