Hi Angel,
Regarding your maid woes, I totally understand how you feel. For me, its a NO-NO with handphones and I told her right from the start. Her agency also banned their maids from carrying hps, all got to surrender to the agency. Upon finishing their contract, then they will get back their phones. Reason being, they might get distracted with handphones, and in your case, get bfs. But I understand its quite hard to control, esp for filipino maids because of the compulsory off days. My maid is Indo, so we pay extra for her no-off days. But she is ok with not having hp. I also told her if I find her having a bf, off she goes back to the agency. As simple as that. But actually agency has already told their maids all these already, so they are quite fearful of being sent back.
For me, why I'm so strict with my maid is that she's looking after my baby, I dont want her to have other distractions, or get into any unnecessary trouble which I would have to take care of i.e. getting pregnant and later having to bring her to clinic etc. And like what one of the mummies mentioned, dont know what disease (touch wood) she will contract. There may be other problems also, like is her bf a married man as well? that will certainly lead to more complications, and what if they broke off and maybe she gets too depressed and it affects her mood and work?
My 2 cents' worth. If I were you, I would probably start looking for a new maid, but an experienced one who has her own children, and not very old, myanmar and indo are pretty good, esp those who can speak basic english.