To the Wolf: Look at the Tiferes Yisroel on that Mishna, and you will find a very clear explanation; that it is a metaphor for something totally spiritual.
It is easy for us to understand it all in the mundane, if it only referred to Tu B’Av – but it very hard to extrapolate that meaning onto Yom Kippur. Do you really think that the boys and the girls went out to the parks on Yom Kippur? When? Before Ne’ila? Or perhaps after Mussaf?
Learn the Tiferes Yisroel commentary in its entirety,and you will understand.