And Sunny you are correct. He had D4 over for the playdate (although the girl there appeared to be D7's age).
I thought I was even toned with STBX about the whole thing but he was FROSTY when I picked up D4 yesterday. Whatever - I'm not going to get stressed about his reactions when I have behaved reasonably.
Sunny - I already ordered the phone. Not only because of this situation, but also because she and her dad like to text each other on the weekends when he is working and tend to monopolize my phone at inconvenient moments. Also - when her grandma was visiting last month - there was some confusion about when she was supposed to get picked up from the bus - so a phone would have been helpful there too. You make a good point about it potentially sending the message that her dad isn't trustworthy - so I may wait a little bit to actually give it to her (it's going to be presented as my phone that she is allowed to use). Frankly, her schedule is so busy and there is so much potential for confusion and misunderstanding, it would make me feel better to know she has a way to contact me.