One funny and subtle thing I've observed about ESTjs are this. When they are feeling bad or low or insecure about something if it's ever expressed, it's expressed as a joke. And that seems like a defense mechanism, if I were to explain it, it would be like , they are experiencing some distress ( whether it be extreme or mild I do not know) but they don't want to seem sensitive so they say it as a joke just incase someone thinks they are weak they can say "Nah I don't really care I am joking," BUT if you actually show concern in how they are doing when they express something like this you might get a more down to earth less jokey response. It's like they are fishing for someone to take concern in their low emotional state BUT don't want to pressure others or appear weak so they have an exit which is "I'm just messing around, I'm fine." As an Fi 4D though, it is easy to tell that the "hurt" is real under the joke BUT the joke is placed so you do not take the hurt so seriously so a subtle approach is required, so instead of asking "OMG WHAT's wrong?!" (since that would be an over-reaction) an EII might just ask "Hey you alright man?" And throw in a laugh to match the playful joke while showing real concern. That fine line between serious and playful seems to be matched there.