Again, once you are AWARE that you are sending someone flirting vibes when you don't intend to, then it is irresponsible to continue (I don't mean "you" personally, but in general). You can be made aware by how the person responds; I don't buy total oblivion concerning response. If that were the case, the ENFJ in the OP's situation would not keep backing out at key moments. Especially in a situation where there is a romantic history is this "obliviousness' an irresponsible cop-out.
It seems the ENFJs realize this, back off, but then pop back up when they need that "soothing". And yes, a lot of people use INFPs to "soothe" them - it's like free therapy. When INFPs catch on & mature a bit, we're usually not so free with it though. I bear responsibility for my actions - I don't show too much concern towards men looking for emotional "healing" anymore. It definitely gives the WRONG idea to show that level of attention, and I'm not interested in leading anyone on.