MacDonalds goings on today

I have been here 30 minutes, a male walks out of the toilets, I never saw him go in. He walks up to a cubical and wakes a female, who I never saw, her head slowly rises, he says a few words then he goes back into the toilets. The female's head slowly descends and I once again no longer see her.
Seems obvious that they have shot up something, but why would the male go back into the toilets?