sounds like the infamous, dreaded, end of the world - wet sumping syndrome, I used the word syndrome instead of problem you will note.
If your bike stands for a good while between starts oil can seep past the pump into the sump, normally it's not enough to be noticeable as once the engine runs the return side of the pump ( has a larger capacity than the feed side ) will quickly clear the excess and normal service is resumed.
If the bike stands still long enough there could be more oil in the sump than the return side can get rid of and oil will be forced out of the sump with air ( via the engine breather circuit ), so the floor marking thing.
If you do a search here for wet sumping you will find many and varied opinions about it and cures and fixes, all valid depending on your preference and circumstance ( avoiding the wrangle of tap/no tap opinions folks).
It's not a problem for most I reckon, probably accounts for the "smokes a bit to start with then clears" remark oft times heard.
Other causes of air being blown out there, - blow by - due to worn rings, bore