aaah that old trick used to be my biggest turn off with latin parlours back in the day, they'd have a photo of two girls and when ever I got there the "hot" girl I initially phoned to see was always busy with a punter that "just" showed up seconds before I got there.
Good that you walked, what side of Streatham was it? there used to be a nice one next to Barclays bank that was easy to get to.