The city of Bangkok is over 600 square miles (1.5 billion square meters).
Throughout your travels in Bangkok, you may meet someone you really like, however, there is a real chance she could be 2 hours travel time or more from your residence or where you stay and still be in Bangkok.
Even a greater chance if you are meeting online.
The traffic and congestion getting around a city this size can make distance dating almost impossible, unless you have the money, time and energy to spend 2 hours traveling to see her.
Sounds strange but it is very true.
It may be ok the first couple of times, however, sooner or later, the trouble in traveling to see each other reeks havoc on the relationship.
Another disadvantage to a city this large in area.