If you are an INTP, being around an ENFP is going to be a mind-blowing imaginative experience. Their Ne is so powerful that it will super-charge yours. You’ll be quite a bit alike in terms of how you process things and see the world… seeing not only what something is, but what it has the potential to be, and how it connects to everything else. ENFPs are also pretty straightforward (high-order Te) in their opinions and views, so you may find their frankness mirrors your Ti-bluntness to some extent.
You will be a little more set in your ways than they will be (due to Si-usage, and their inferior Si), but their energetic approach to life will encourage you to try out new things more often. You’ll find fun, creative things to do together that will inspire your imaginations, but since both of you tend to have short attention spans, you need to keep it interesting. The biggest potential source of conflict will come if your Fe doesn’t always like how their Fi interacts with other people (no compromises on things of importance), but most ENFPs are polite, open-minded, non-judgmental, and easy to get along with if you let them have their space.
Fi-users tend to be very passionate about things that they feel strongly about, so if you are platonic about something that is vitally important to them, it’ll be hard for them to understand why you don’t care more. They will also want to leap into things quicker than you do, because it doesn’t have to be processed through introverted thinking (and make logical sense first) for them before they are eager to try it out or do it. Though typically outgoing, they’re not as extroverted as some extroverts, so they won’t keep you constantly on the run and will enjoy time alone.