One of my poly fren get to know his gf by picking up his gf's
wallet.
I mean he picked up a wallet, and found that the girl is quite
chio(I wonder if it's not a chio gal, will he return the wallet),
so he contacted the girl and give her back the wallet with
everything inside, and then later ask her out, eventually become
his gf.
This is kind of reverse for your case, bcos it's the girl who
picked up your fren's mobile phone, not that you picked up her
mobile phone. And there's this "fren" of yours involved, not just
you(TS) and the girl.
