There was recently a thread about ENFP + ISTP couples & how odd it seems (given how it defies all type theories about both being intuitive or both Fi/Te or a P & J complement, etc).
I've noticed the same phenomenon with INFP + ESTP. As an adult, I draw ESTPs a lot in dating, but I also quickly see the problem with it ever being long-term/serious. There is a weird draw hard to explain, because in many ways we're opposites, but not like how it is with ESTJs (who I have a much stronger gut reaction to, often negative).
I know some INFPs around here are dating/have dated ESTPs, so add what you like to this. Bringing enneagram into this could be interesting also.
The obvious draws are both having Pe mentalities (although INFPs are behaviorally Pe in a more subdued way). There's an exploratory approach to life. Then there's a possible shared interest in/appreciation for aesthetics, which will likely come from very different perspectives still. One being very much a doer & liver of life & the other a dreamer & more cerebral creates a "fascination" effect. The INFP may like the idea of such a person "handling" all the more physical aspects of reality (ie. making money, navigating the social realm, planning activities) without being controlled or suffocated, as they may fear a Te-dom would do; and the ESTP may like to leave the moral, spiritual & philosophical musings & higher brow taste to someone who isn't going to "nudge" them condescendingly like an NFJ might. On the surface, it may seem like "this person covers a blind spot without being a threat to my preferred style!".