I (my parents) did it twice...
The first one was 2 hot German guys, we were 15 y/o. I spend not that much time with them, I don't speak German, I don't remember if they speak French. But we played football (soccer), and some video games, but nothing more.
The second one it was one English straight guy from Peterborough (I went to his house as an exchange students), my school and his have/had (I don't know if they still do it

) an European partnership to all classes of International Trade sections. I was 18, he was really nice, I introduce him all my friends (he hooked up with one of my friends), we partied quite a lot. The year after at his house, it was crazy, we were like the 2 brothers. I love his family, he loves mine. We are still in touch and we do have see each other at least once a year (Except when I spent 2 year in London for my business school, I saw him like every weekend).