"If you find that too difficult, next time your shagging your wife tell her that you're the father of her sisters baby"

That won't work.....I have a vasectomy, smartest thing I'ever done.

the maid's boyfriend should have gotten one a year ago.

hey my sister in law is also the maid! she started slacking and becoming lazy i complained to my wife who gave the dont worry attitude i told ok she could do the stuff the sister in law wasnt doing after she came home from work, was ok for a couple of days until it started to mess with her playing badmington with her friends after work, she soon got her sister back in check!!

Your in the situation now so make the best of it. Pay the sister and let the wife deal with problem.

I still don't understand why people hire maids unless perhaps both are working full time jobs. Even then I wonder if its really necessary.

I know the cost of hiring a maid is cheap in Thailand but really did you have one in the part of the world you came from. My wife and I get by without hired help by splitting the work. Its not hard and takes only a couple hours a day at most.

good for you. do you mean your wife gets by or do you do your own laundry and clean your own toilets?

A buddy of mine had a similar problem. The sister in law wasn't pregnant but was supposed to live rent free while she worked at 7-11. She agreed to help out around the house in exchange for room & board. She soon resigned the 7-11 job and started watching Thai soaps all day long. My buddy "evicted" her and she moved in with another sister.

When it starts out bad, it never gets any better...

OP: Your obligation is to pull out in time. And hers is to swallow if you miss. Anything above that is clearly outside your responsibility as an employer.

Ps. never, ever, hire family as staff like this...it can never go well. Ds.

You employed your sister in-law as a maid .... what were you thinking?!

.... Don't tell me... you weren't thinking

I'm sure he had absolutely no say in it guesthouse. I feel this pattern is set to continue.

My question is 'what is my obligation?', as her employer....do I pay her full salery for the month that she is out of service??

The OP admits he's her employer. Therefore he has to abide by what other 'employers' in Thailand are obliged to do in the same circumstances. That is, to pay her the one months money, no more. I think he already knows that.