Do not be like Judas Iscariot.
We must stay until the end of the Recession; when the priest leaves the Sanctuary.
Leaving early after dinner with family or friends is OK, but leaving early after Communion is NOT OK. The Mass is not some ordinary social gathering or service. The Mass is the celebration of the paschal mystery, the life, death, and resurrection of Jesus Christ for the salvation of the world.
We are made present at Calvary when Jesus Christ was crucified for our sake, and you decide to leave early?
Do not leave early than the priest. In fact, we also encouraged to stay and take a little time to pray. You are in the House of God after all.