Can you get pregnant in a spa from pre-ejaculatory fluid?

Answer 1

The suggestion that seminal fluid might travel through the water is practically impossible, even more so at elevated temperatures (which would rapidly deteriorate any sperm). Preejaculatory fluid will usually only contain minute amounts of sperm.

However, anytime an uncovered penis is in proximity to the vagina of a female (especially an uncovered one), there is the potential for sperm to reach the vaginal lining. Underwater sex is no safer than anywhere else. But any significant chance would require direct contact between the male and female genitals, because of the deteriorating affect of heated water.