I HATE IT WHEN THAT HAPPENS: UK navy mistook farting whale for phantom Russians trying to track their nuclear subs.

The UK’s Royal Navy launched a frantic search for phantom Russians off the coast after picking up two mysterious sounds in the ocean — only to conclude that the noises came from a gassy whale, an official told The Sun.

Naval officials feared one of Russian President Vladimir Putin’s drone subs had dropped a listening device onto the ocean floor between two islands in Scotland and let rip on an investigation.

The two toots were detected about 100 miles from where the UK’s doomsday subs are based.

“We have been analyzing the sounds and now believe it was a marine mammal. A whale,” the official told the British newspaper.

The sound, first described by analysts as a man-made noise, had never before been picked up on the sensors — leading the navy to confuse Das Boof for Das Boot, according to the report.

To be fair, Russian subs are pretty noisy…