Josh Allen, Hailee Steinfeld Look Smitten In Gender Reveal Video Cameo

Josh Allen and Hailee Steinfeld's romance is starting to feel real serious ... as the two couldn't have looked more in love during a cameo they recently did for a baby's gender reveal.

The video was posted on TikTok on Sunday ... and in it, several family members and friends -- including Allen and Steinfeld -- appeared on screen to guess the gender of Allen's sister's unborn child.

After introducing themselves, Allen and Steinfeld both predicted it'd be a boy -- but check out the footage, the two looked super smitten with one another.

Josh appears to have his hand on her lower back -- and at one point during their short appearance, Hailee stumbles and braces herself with the NFL star's core. The two also flashed big grins throughout.

The couple has been pretty much inseparable recently -- they've been spotted cruising around the Los Angeles area a few times this offseason ... and they were also looking lovey-dovey during their trip to Paris Fashion Week earlier this month.

In fact, they've gotten so tight -- Allen's Bills teammate, Dion Dawkins, proclaimed in early March the quarterback "is in love."