Gorillas Filmed Mating at Zoo in Front of Shocked Visitors

Talk about a jungle joyride -- two gorillas went completely bananas for each other, tossing modesty into the bushes, and getting busy in broad daylight ... giving stunned onlookers a surprise mating call they definitely didn’t sign up for!

The clip was filmed Monday and it’s pretty NSFW -- don’t say we didn’t warn you -- capturing a much larger gorilla mounting a female inside an enclosure at Belgium's Zoo Antwerpen ... and yes, the background audio makes it painfully clear there were kids watching the whole thing go down😳.

It’s a jaw-dropping clip, we get it ... but being there must’ve been next-level unhinged, with the pair going at it as adults nervously laughed, cringed, and clearly had no idea where to look.

Wild as it looks, the zoo says this wasn’t some rogue ape behavior. The male silverback, Ayo -- who joined the zoo in November as part of a European breeding program -- was simply doing what comes naturally. Translation: He don’t chase -- he swings.

Officials added natural behaviors like mating can happen at any time and may be visible to visitors ... basically confirming that the zoo experience sometimes comes with zero warning and no parental advisory.