Hang on, your current T? Or ex T? I know someone who is friends with their ex T and actually it all seems fine. But they did wait over six months before meeting up, and my friend has a new T, so those things helped.
Current T? In the UK I believe that would be incredibly frowned upon by all the ethics boards, and may well lead to inquiry. I know some dual relationships are unavoidable, eg kids at the same school in a small town, but a T has an implicit and explicit duty to avoid dual relationships with clients.