at last, it's time for his pr prompos promposal. he strides to the stage. his girlfriend's jaw dropping response, worth the wait. >> move over, there's a new captain. mcken in a, i have your ticket and your suitcase packed. will you go to prom with me? >> yes. [ applause ] >> reporter: once a promposal is posted online it gets an instant viral boost when twitter handles and hash tags are around them. a 17-year-old promposal is the kind people love to like on twitter. >> everyone comes up to me the next day at school, thanks a lot. now ours will look not as good. >> reporter: he rented a plane and then flew over a street where he'd written prom in chalk. the object of his affection was thrilled. >> i got 160 likes on insta gam. that was cool that it got that many. >> last year i got her a sign that said i meant to ask you prom, and i had a bunch of peppermints. >> that was homecoming. >> last year for prom you wrote it on my car. >> right. >> reporter: as extreme promposals become the norm, an author worries it can ad to the pressure of fitting in and or bei