Guys,

Yes just you boys, I'm sure you're clued up on travel safety but I'll say this anyway...
......NANJING LU.......
Do NOT accept any invitation to a bar or coffee shop from young women, or even men nowadays, to help them with English, French or any language, study, thesis etc unless you want to pay anywhere between 500-3000RMB for the pleasure of a whisky!
It's not illegal as the prices are displayed, and the bar will deny all knowledge of your 'friends' association with them, they send in the heavies if you refuse, luckily as I'm in a relationship I never get approached but my colleague had 300 conned in this very way, and stories abound about many more cases! Be wise!

The most infamous cafe is above a jewelers.
Think about it, if they are genuine students they'll happily accept a Starbucks or McD coffee!