This character is considered to be promiscuous. They engage in sexual activity frequently and indiscriminately with different partners.
Promiscuous characters sleep around not for money like a prostitute, but for their own satisfaction.
A term frequently applied to an individual who is considered to have loose sexual morals or who is sexually promiscuous is a slut.
The term is generally pejorative and most often used as an insult, sexual slur or offensive term of disparagement (slut shaming). However, in recent times, there have been attempts to "reclaim" the word, while some individuals embrace the title as a source of pride.