No, there were two videos, and the first had O'Keefe posing as a pimp with a woman posing as a pregnant 15-year-old -- on a phone conversation with Planned Parenthood.
The videos are no longer available, as they were ruled to be a violation of California law regarding secret audio recording (it's a two-party state).
That was Acorn.
It in the ACORN videos that he posed as a pimp and a different woman as a prostitute.
Breitbart was accusing Podesta and several others of defending Planned Parenthood, and apparently lumped these together.
That was the ACORN sting you are remembering, the one Breitbart was referring to was a sting on Planned Parenthood: