There's a "dirty" secret behind The Bachelor's tough mudder date.

There’s something you didn’t see on last week’s group date, where Richie challenged the girls to compete in a mock ‘Tough Mudder’.

No, it wasn’t Olena crawling through mud like a lizard, because we definitely saw that.

And we most certainly saw Rachael and Alex competing shamelessly for Richie’s attention.

READ ALL OF ROSIE’S BACHELOR RECAPS HERE.

What we didn’t see was the girls being hosed off and then re-covered in dirt for their on camera interviews….wait, what?!

That's right. If you were wondering why the girls still looked super muddy after a) swimming through a pool of ice cold water and b) hosing each other down post race, Osher just lifted the lid for you.

On the week six 'Insider Guide', the Bachie host revealed that the girls had to be smothered in mud after cleaning off in order to appear more messy for the cameras.

"In typical television style, when it came to doing their interviews, they had to cover themselves in mud all over again," he revealed.

That might explain why Olena went from this:

To this:

Luckily, all the girls agreed that the messy, dirty date was "the best group date so far", so all that mud was definitely worth it.

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