There is no mechanism for the remaining 27 countries to boot us out of the EU. It is up to the UK to invoke Article 50, and until that happens we remain full members with full rights, and full obligations. The only way they could expel us would be for all 27 other countries to invoke article 50 themselves leaving just us in the EU.
I was a remainiac, but accept the result of the referendum. The only way I think a second referendum could possibly be justified would be if the EU came back to us and said something like we've had a rethink - you can have border controls, limits on free movement, exemption from future EU laws, primacy of UK courts over the ECJ blah blah. That would address most of the issues British people have with the EU, and remove the endless aggro that is going to go on for years when we do Brexit. However, the EU won't do that - they had their chance when Dave went to them before he called the referendum and basically blanked him.
So it's now up to the UK to invoke Article 50, and Junker et al can go swivel if he thinks he can affect the timing. Personally I think the timing will be done to best suit the Conservative party. They'll want us to be out before the 2020 general election, but not too long before it in-case things go pear-shaped rapidly. GE is May2020, so say they want to be out 6-9 months before that - Oct2019 after everyone has had their last Summer Holiday in Majorca/Crete/Cyprus. That means invoking Article 50 in Oct2017.