All I can say is, if the INTP isn't sure of the ENFP's intentions...telling someone to date others...she was probably looking for the opposite response. I'd say it was a gambit to call the ENFP out!
Sort of like "this person really likes me. If I tell him to date other people it shouldn't affect him because he wouldn't do it anyway since he likes me so much...and if he does date others then he really didn't like me that much anyway." After all, there's a certain logic to it. To an INTP...lol...If you really like someone you don't want to date anyone else, right?
This is INTP "uber" logic at work and therefore has many a blind spot. This is a great example of how we end up sabotaging ourselves.
When things get this complicated...just act and quit thinking! ...Wait...that's how INTP's sabotage ourselves too. One extreme to another. :sigh:
I agree that we do have a tendency to sabotage ourselves by over analysing this way. But what I was trying to say in my previous post is that I would never do such a potentially emotional devastating test unless I felt like I had everything to loose, which is a very insecure thing to think.
I think an INTP who is convinced of his or her own capabilities would rather just make observations in a familiar situation, then take a more detached view and ponder these observations for as long as necessary.