This answer cites a verse from the Devi Bhagavatam:
Then those prostitutes of the Devas, dressed with their heavenly ornaments and the heavenly flowers, appeared before the Munis and bowed down their heads on the ground.
The part in bold is referring to the Apsaras, otherwise known as celestial nymphs. Their job is to basically go around and have sex with everyone who has been rewarded with heaven.
Here is another verse from the Mahabharata:
"We Apsaras are free and unconfined in our choice. It behooves you not, therefore, to esteem me as your superior. The sons and grandsons of Puru's race, that have come here in consequence of ascetic merit do all sport with us, without incurring any sin. We have no husband, no sons, indeed, no relations."
Are there any other scriptural verses that talk about the sexual services provided by the Apsaras?