Precariously adding a gay male protagonist to its acknowledged amalgam of teen-comedy tropes, G.B.F. gets steadier as it gathers momentum. Picture a cartoonishly colorful high school where a trio of prom-queen contenders do bitchy battle to acquire that ultimate fashion accessory, the “gay best friend.” Somehow the only candidate is our unassuming narrator, Tanner (Michael J. Willett), accidentally outed via hookup app by his swishy yet still-closeted bestie, Brent (Paul Iacono). Expectedly, Tanner falls out with Brent but falls in with brassy blonde Fawcett (Sasha Pieterse), drama-club diva Caprice (Xosha Roquemore), and prissy Mormon ‘Shley (Andrea Bowen), whose collective makeover-montage attention inevitably goes to his head. Politically gentle but winningly averse to any kind of piety, writer George Northy and director Darren Stein make sure to practice equal-opportunity mockery and, eventually, mercy. Their implied plea to normalize coming out as just another coming of age seems generous, if simplistic, just as Megan Mullally seems funny but in her comfort zone as Brent’s too-eagerly supportive mom. No amount of catty, witty wordplay can quite make up for creaky sitcomish contrivance, so the movie strains itself even at its most brisk. But especially in light of closing-credits outtakes suggesting a good time was had by all, the takeaway is its sweetness.