i've basically only seen two Mistresses, and been lucky enough to have had special rapport with both.

i started with Mistress with 2 hour sessions 20 years ago, and on special occasions (birthday, anniversary) would extend to 4. And i'd done a few overnight.

When i see the incomparable Vinyl Queen, one of us will be travelling and it is not all that frequent, so my base for Her is four hours now.

i think i'm to the point now where my answer might be "infinite". Honestly, i can spend 8 hours with Mistress and miss Her the next day.