A key difficulty in the study of Milky Way massive stars and OB associations has been the large uncertainty in their distances, hindering the comparison with theories of stellar and cluster evolution. The recent second release of data from the Gaia satellite has provided unprecedented high quality astrometry for more than 1.3 billion of objects, all of them with measured parallaxes. For the first time ever, we have explored the spatial substructure of the Cygnus OB2 association using parallaxes from the recent second Gaia data release. We used a Bayesian inference procedure to model the observed parallax distribution. Our analysis reveals a foreground group separated from the main Cygnus OB2 population. This result could unravel the internal kinematics and evolution of this massive star-forming region.