While dating a girl - particularly in the first awkward weeks - speedshitting refers to the act of taking a very fast shit in her appartment's/dowm room's bathroom, as to induce her to thing you were only - harmlessly - urinating.
Girl: "We spend a lot of time together...but I noticed...err"
Boy: "Yes?"
Girl "You...never seem to do a numer two!!"
Boy "Well...I was speedshitting"
When your partner keeps overly meticulous track of expenditure in the relationship pertaining to what you "owe" them, to the detriment of your physical relationship.
He was spreadsheeting every condom he bought and used with me. I had to pay him at the end of the month.