In the 60s I did a French exchange at 14 and a German one at 16. My French came on enormously during those 3 weeks but the trip had its awkward moments. The family had a small square bath which nobody ever seemed to use - it was apparently used for storage, and there was no,lock on the door! I was permanently petrified that Monsieur would barge in in his Y fronts, as he did once when thankfully I was dressed.
We had all been v worried on the boat over that we would have 'bucket and chuck it' loos. Consequently after about 10 days I had a postcard from a friend staying elsewhere that ended, PS, we haven't got Turkish toilets!
German exchange had none of those pitfalls, and again my German came on a lot. But I was also hideously embarrassed after a minor leak in the bed when my period started. The Mutti didn't mention it as such, but later when I wanted a bath she said anxiously, 'KANNST du baden ?' - since she thought it was verboten when you were On, as we used to say. And I well remember her daughter, my exchange, lamenting bitterly that she was not allowed to wash her hair while on. 'Ich kann es nicht mehr leiden!' (I can't bear it any more!). Such expressions still stay with me.
Daughter did both Spanish and German exchange and the German one produced an interesting little snippet. Daughter was wriggling around and trying to explain to German counterpart, 'My pants are up my crack!'
Eventually the penny dropped. 'Ah!' said the girl. 'Meine Unterhose klampft im Arsch!' ?
(mein Gott, the iPad autocorrect is even more annoying when you're trying to type in another lingo!'