I would say no, but also that it was described as unlawful, so was it a marriage at all? Certainly David + Bathsheba round 1 was both dishonorable and unlawful.
It seems the point of that verse is that we should honor/respect the marriage of all(others and our own), and the marriage bed is to be undefiled, the sexually immoral and adulterers God will judge. So that would imply that the state of marriage is something to be honored.
"David sent messengers and took her, and when she came to him, he lay with her; and when she had purified herself from her uncleanness, she returned to her house. 5 The woman conceived; and she sent and told David, and said, “I am pregnant.” 2 Sam 11
David lays with Bathsheba, who is married to Uriah, and that sex does not make her David's wife or break apart the marriage to Uriah by default.
"Now when the wife of Uriah heard that Uriah her husband was dead, she mourned for her husband. 27 When the time of mourning was over, David sent and brought her to his house and she became his wife; then she bore him a son. But the thing that David had done was evil in the sight of the LORD." 2 Sam 11
It seems it was only after Uriah her husband had died (and so she was no longer bound) that David was able to take her as a legitimate wife. But he had already had sex with her
and a child was produced.
So sex with a married woman (adultery) does not break the original marriage, only the death of the husband, or his divorcing and sending her away, or her death obviously (if the full punishment is carried out).
I think this backs up @therevoltingman's point on *proper* divorce (and I'll add, death) is the only thing that breaks a one-flesh union created by God. No man, including the husband himself, should separate what God has joined together, except for sexual immorality.
So the question is still, what is a union that "God has joined together" ... it
could be as simple as a man taking a woman, and having sex with her, after that she is his, but that creates some issues imo.
In the case of a harlot who is sleeping with many men, is she just entering into and out of one flesh unions (marriages + divorces) merely by the sex + the leaving of the man, or is she not actually bound to any of them because
none of them claimed her as their woman/wife and she doesn't claim any of them as her husband?