There is a saying, things happen when we expect them the least. It’s very true regarding pregnancy, even a guy never failed before. The girls and situations really differ.
The main difficulty is that we never know our hookup well enough to ask her whether she is currently having her risky days. Most of casual affairs are very sporadic and unplanned.
Yet, it never hurts to ask this question prior to sex or even in a middle of it. Otherwise, the sudden discovery in a few weeks after might be too unpleasant and discomforting for you.
On one hand, no one bears any responsibilities in a casual relationship to speeddate. On another hand, it’s harder with friends with benefits who expect some help and understanding from us.
Since not all casual lovers are complete strangers to us, the inconveniences are highly possible in these conditions. If you are afraid this can take place, better get laid anonymously only.
So, regardless of which form of hookup you’re currently having, always be equally careful and prudent in matters of baby-control. It does happen that casual sex ends in unexpected pregnancy.