Daniel, I have been living and working in China since 1989 in many different places. Whereas back in that day, it was a litle uncomfortable for the Chinese girls (women) dating a foreigner I never heard of a foreigner being sent to prison for this. China is very modern nowadays, unless of course you are way out in the countryside or in a minority area, and now even showing affection in public is acceptable. Don't listen to would be "experts" about anything, come and check it out for yourself. If having a Chinese girlfriend is that high on your priority list for coming to China, then stay at home!