I give mine the money I was prepare to pay, and tell her to keep the change (or pay the excess herself). Never any over-ordering, unlimited 'open wallet' is a bad idea..
No relationships are 'genuine', if they were the women (western or not) would have always contributed 1/2 the cost of every 'date'. They would also be paying half the home purchase price and buying themselves life insurance.
The main differences between a western and Thai relationship being the Thais don't try to hide what's happening.
In the west generally 3x dinner = 1x sex (maybe)
In Thailand we can just hand her the money and not have to waste time with 'dinner'.
I normally use 50 units/month, so my bill will go up by 50bht- the discount on the standing charge. But it will reduce my solar payback time by 1-2 years (with the batteries it previously was 7 years).
It's based on the date from which you choose to start taking your pension.
Alternatively, you could not tell them you live in Thailand and get an increase every year.
Mine was in Chinese and the English translation didn't make much sense.
But it still turned the electric off (no flash, bang, spark) quicker than the fuses could flip when it got shorted.
(daughter + iron + extension lead = short)
Fairly common in the USA, or so I'm told.
In the UK they nearly all expected 3x dinner and drinks for 1x sex.
Can't remember much success when they paid for themselves.