From the way I understand the rule, at least for psychologists (I don't think your T was classified as that, right?), it's 2 years (at least) before a friendship or romantic relationship. I don't think it's necessarily 2 years of no contact. I've had a bit of email contact with ex-T (though she's a social worker) and some with ex-MC, and it's definitely been less than 2 years. But, that's different than, say, an actual friendship where we might meet for coffee. Ex-T told me that under the rules of clinical social workers, she's NEVER supposed to become friends with a former client, even if it had been, say, 10 years. Which is more strict than with psychologists.

More in a bit.