using rsync to delete copied files

[LuKreme]

OK, I have DIR1 which contains several thousand files. I have DIR2 that mostly the same files.

I want to delete all the files in DIR1 that exist in DIR2. I don't want to sync them, I don't want any new files in DIR2.

I can't get my head around if this is doable with rsync.

-- 
FOUR QUEENS. HMM. THAT IS VERY HIGH.  Death looked down at his cards,
and then up into Granny's steady, blue-eyed gaze.  Neither moved for
some time.  Then Death laid the hand on the table.  I LOSE, he said. ALL
I HAVE IS FOUR ONES.