Would you worry about him texting/calling his ex from your own phone daily?

I just met a guy on craiglist. Well actually he admitted it was his EX girl who set up his account and emailed all these women for him...I guess that's cool. Thing is he calls her several times a day from my phone when Im with him (he doesn't have a phone right now) and she does him favors and stuff. I guess they could just me good friends right?* o and she still has access to all his emails and facebook pwords :/ hmmmm