[PapaBear3625]

Another factor that determines boy vs girls is that Y sperm are faster swimmers, but have a shorter lifespan than X sperm. One method that tries to take advantage of this in order to shift the odds in favor of boy or girl is the Shettles Method.

[POWERSBOOTHEFAN]

What about a woman who had sex with more than one man around the same time?

I thought I heard something about “dueling sperm”.