My experience,, if you have a Thai wife and meet a few requirements a UK visa is a given, if you have a girlfriend with little or no money other than a big deposit the week before the application, if the girl friend has no job or employment history and has 3 children she is supporting, save your money it won't happen, however if your girl friend has stable job like a nurse or bank official with regular monthly income and a letter from her employer that her job remains for her whilst she is on holiday tick a few more boxes and your in, it is for the consular official to get a view from the application that it is a holiday and she will come back at the end of the stay, if the UK make it visa free,. Look out.