So, it happened quite a few times so far.
I was sitting on a bench in a touristy area in Cần Thơ enjoying a cold beer after a long week of work, then a mother and her young daughter would approach me and the mother would ask me to talk to her daughter. Since I wanted to practice my Vietnamese, the daughter was talking to me in English and I was answering in Vietnamese. The mother told me "English only". Alright, I did switch to English. The daughter would talk to me for a while but after 15 minutes I've had enough and I left.
It happened a few more times in the past few months, around town.
This week, I was at a "quán sinh tố" ordering my drinks in Vietnamese and a mother (with her son around) would jump on the occasion (she didn't speak English) and ask me for my Zalo. I asked her why she needed my Zalo. She said for her son to "practice English". Well, I've had enough. I told her I was working a lot and when I'm free I want to have fun, not to speak (or indirectly teach) English for free. She said thank you nonetheless, at least.
I guess this is a bit of a rant and I've had the discussion with a few people (my Vietnamese teacher thinks it's bad behaviour from their part, lack of culture) but does this happen to any of you and how do you deal with this? I don't want to be mean to the people asking me this (especially that these kids don't deserve my frustrated attitude) but at the same time why the heck would I spend my free time speaking English with whatever stranger to help them improve their English? Do they think my time is worthless and I've got nothing else to do? Even my Vietnamese teacher, who's very considerate, asked me if I could talk with one of her English student once a week for an hour and that her parents "would pay me". Well, she suggested 200k. This is only a fraction of my hourly salary (software development, nothing related to teaching), so again, how/why would they think any foreigner would provider their time for this amount? They know Westerners make much more than that, they're aware of it.
Thanks in advance for your wise insight