That was the very first thing that happened, when Manolis and Koula announced the Greece holiday Aisha said it was 2 days after (or before) the special holiday they had booked together in Bali, so she couldn't take any more time off work. Sounded to me as though that holiday was intended to be really special, a bit of a make or break thing to them, I assumed that was because of Hector and his infidelities or similar, but maybe not, remember at the BBQ he was really going for Connie, that only changed after the slap, I assumed he had a track record for it.
So I think Koula and Manolis already knew about the Bali holiday and had no intention of letting it happen, clearly Aisha is not deemed good enough for their precious son. Who, after seeming like a complete shit at first is becoming one of the characters I am more sympathetic to. I love all the twists and turns, Harry has also been made more easy to sympathise with now, but remember he is unfaithful, takes drugs, is physically rough with both wife and lover, treats his employees like shit and lets this all play out in front of his child.
I am still puzzled a little bit by the Anouk episode, it was interesting in it's own right, and clarified that there was a strong and long-standing bond between the three women but she really has't been central to the storylines like the other characters we have followed.