Recently, Superman managed to warp his personal timeline—and maybe even vast swathes of the DC Universe—by merging both his New 52-era and Pre-Flashpoint selves into one single Superperson. While we still don’t know the full ramifications of what’s been affected, we now know one thing: Clark no longer snogged Diana.
Source: io9 – Superman Managed to Retcon His Romance With Wonder Woman Out of Existence