Jason Derulo Buys $3.6 Million L.A. Home for Son's Mother Jena Frumes

Jason Derulo and Jena Frumes are co-parenting their son without a hitch, under completely different roofs -- and she's doing so under a brand new one ... TMZ Hip Hop has learned.

The R&B/pop star leveraged his Billboard and TikTok success to purchase a $3.6 million, nearly 5,000 sq foot fortress back in March, but it wasn't for himself. We're told Jena and their son Jason King live there exclusively, with plenty of room to, ya know ... wiggle.

The swanky pad checks off 5 bedrooms and 5.5 bathrooms and features a pool with built-in spa and waterfall features, a soundproof movie theater -- plus an outdoor farmhouse and BBQ area.

Jason copped the house this past March amid a career resurgence that saw his TikTok following and bank account swell substantially.

Fans were initially shocked to see Jason support Jena at her recent runway gig during designer Luli Fama's Miami Swim Week show ... especially after cheating allegations fractured their relationship last September.