Not going to happen, major reason for annexation was to keep Sebastopol as the major/only Russia navy base in the Black Sea. That reason will never vanish as there are no other suitable locations to relocate that base.

> I wonder how long it will take for russia to get tired of subsidizing crimea and they will beg to go back to the ukraine.

Starting already. I mean, more than before. I found Crimeans not very understanding Russia's realities, so now even thought money go to Crimea from the rest of Russia, the people in Crimea start to compare unfavorably to the alternative.

History moves slowly. However, Ukraine going closer to Europe would be a good illustration.