What's so unrealistic about priests and nuns getting pregnant? Hardly a day goes by without us reading something new in the newspapers about priests, across all hierarchies, abusing orphans and altar boys who were in the care of the clergy. Some of the cases are old, others current. And here, there will be not only homosexual assaults, but also heterosexual ones. And under the roof of the church there is certainly not only sexual abuse, but also secret love affairs. And where sex takes place, whether forced or out of love, whether secret or not, there is of course the chance of pregnancy. Furthermore, not all religions insist on celibacy. There are also sects that are clearly sexually oriented. The only thing that distinguishes sects from public religions is their organizational structure and the number of their followers. If all this is the case in reality, why should it be any different in games?
Where in reality did they meet halflings?
If they existed in reality, they would be a humanoid species, an alternative evolution, alongside humans. Therefore, probably mammals too. Where would their offspring come from if not through pregnancy?