a variety-seeking woman

In my language, there is an adjective that is ascribed to men and women who want to have many different sexual partners. In other words, they seek to have a great degree of variety in terms of their sex partners. This adjective literally translates to "variety seeking".

Example: She is a variety seeking woman. She has slept with many different men.

Is there a word, adjective, expression or anything in English with the same meaning?

I already know polygamous. But it's a bit scientific!

And what is the opposite? A person who only wants to have one sexual partner?

Solution 1:

The word describing a person practising such behaviour is promiscuous.

promiscuous adjective

1: having or involving many sexual partners : not restricted to one sexual partner or few sexual partners

[Merriam-Webster]

............

• I suppose I was quite promiscuous in my youth.
• It's a fallacy that gay men are more promiscuous than heterosexuals.

[Cambridge Dictionary, which also adds the caveat 'of a person'; though this is the major usage, broadenings are quite common.]

..............................

A nearish-antonym would be 'happily married', though it's not an exact opposite.

One sense of monogamous, in fact the one (as a noun) Merriam-Webster lists first (most common), is a near-antonym, but the base meaning is 'the practice/law of marriage to no more than one partner at any given time':

monogamy

1a: the state or practice of having only one sexual partner at a time

• young couples who practice monogamy

Solution 2:

How about playing the field?

to hold an interest in a number of people or things, especially to become romantically or sexually involved with a number of partners

Cambridge

This is an informal and fairly neutral way to put it.

The opposite would be committed:

Definition of committed relationship: a serious and lasting romantic relationship with someone

MW

For example, in Taylor Swift’s The Man:

They'd say I played the field before
I found someone to commit to