A phrase which implies unfortunate
events are beginning to happen to someone
for offending someone
else. The offended person
"welcomes," or threatens, the offender "into," or with, an unpleasantry as punishment, suggesting that the punishment is not a nightmare which the offended person
has had, but a nightmare in which he/she controls what may be like nightmare for the offender.
If you think you're going
to be able
to threaten me, my wife, and my children without any consequences, you're mistaken. I will tie you up, castrate
you, and starve you every day for each threat. Welcome to my nightmare.