Nick Jonas ain't the only one dating up ... add DJ Flume -- one of the hottest EDM artists in the world -- to the list because the 26-year-old is now dating 40-year-old and best-selling author, Kelly Oxford!!
Sources tell TMZ ... Flume and Kelly have been dating for several months. They met at a house party last fall and they've been going strong ever since. The Australian DJ -- with more than 1 mil followers on Instagram -- shows up on her IG as far back as November 2017.
Kelly -- who has 3 children -- was shamed earlier this year after posting pics from a sexy photo shoot. Unclear where the hate's coming from ... she's a smoke show and she's also a badass who can hold it down in her own right. Kelly's written 2 books -- including the New York Times Best Seller "Everything is Perfect When You're a Liar" -- and a couple screenplays.
She's also on powerhouse William Morris Endeavor's speakers circuit roster. Again, total badass.