sociosexual

Sociosexual orientation (or sociosexuality) is the individual difference in the willingness to engage in sexual activity outside of a committed relationship. Individuals with a more restricted sociosexual orientation are less willing to engage in casual sex; they prefer greater love, commitment and emotional closeness before having sex with romantic partners. Individuals who have a more unrestricted sociosexual orientation are more willing to have casual sex and are more comfortable engaging in sex without love, commitment or closeness.

This is a rather new term I think, 2014 being the first time I have encountered it. Sociosexuality is a psychological or clinical term for promiscuity, or the degree of it, i.e. high or low.