Swallowing semen is a good thing.
"In a Dutch study of women who engaged in oral sex and swallowed the semen, the researchers found that swallowing semen was associated with a lower risk of preeclampsia. One hypothesis for this is that substances in the semen adapt the mother’s immune system so that it accepts foreign proteins present in sperm, as well as in the placenta and fetus. This maintains the blood pressure at a low level and thereby reduces the preeclampsia risk.
Research has also shown that some women are infertile or miscarry due to the presence of antibodies that destroy the proteins or antigens present in their partner’s semen. Having oral sex and swallowing the semen of the partner may help make the pregnancy safer and more successful as the woman is swallowing her partner's antigens.
Work carried out by reproductive expert and psychologist Gordon Gallup from SUNY-Albany suggests that swallowing semen could provide a cure for morning sickness. Gordon hypothesizes that pregnant women vomit as a result of their bodies rejecting genetic material in the sperm as a foreign substance, but that by swallowing and ingesting the sperm of the baby’s father, they can build up immunity."
I learnt quite a bunch of stuff in the last 10 minutes about semen