Acts17apologetics denounce sexual promiscuity; Islam allows concubinage?

In answer to the video "The Truth about Ramadan (David Wood)"

If we start rejecting prophets for having had sex with a concubine, then not much of the biblical prophets would be left. This youtuber is here attempting to misrepresent, with his biblical paradigm in mind, what a concubine is in Islam. 

Besides those that already existed in the society and households before Islam, ma malakat aymanukum are not free persons randomly captured and enslaved or acquired through trade since the Quran only allows the enslavement of captives taken in defensive war campaigns, and only after the threat of war has been subdued meaning their seizure could not be an objective of going to war 8:67,47:4.

In fact the prophet dismissed from fighting those that were more preoccupied with the prospect of capturing potential concubines.

Ma malakat aymanukum, simplicitly rendered "concubines" by the opponents of Islam, are people from both genders, men or women, who were neither freed as a favor nor ransomed, but singled out from the rest of the captives and taken under a guardian's wing in his household because obviously not all captives were taken in. They also become sexually lawful outside wedlock to the guardian that has taken charge of them. 

It is to be noted here, although they can be treated as concubines, this however does not mean that they systematically were. The prophet had in his household several such women living side by side with his wives, to aid and assist for the daily and nightly tasks of receiving at anytime people seeking all kinds of advises and help.

The right hand possessions are people from both genders as already pointed

24:33"And (as for) those (Walladheen) who ask (Yabtaghoona) for a writing from among those whom your right hands possess give them the writing (Fa Kaatibuuhum)"

Ma Malakat aymanikum must cover both males and females because if they were only females it should be "wallaati" or "wallaa'i" instead of Walladheen, "yabtaghuna" (without the waw) instead of Yabtaghoona, "Fa Kaatibuuhuna" instead of Fa Kaatibuuhum. This further proves that the expression, right hand possession does not automatically denote concubine relationship, and anyone claiming the opposite should be able to prove that it was accepted for male or female guardians to have sexual relations with their male right hand possession. Verses such as 24:33,58 speak of those MMA and how they should mingle with the rest of the household. 16:71 is a warning to those guardians who fail to live up to their moral and material responsibilities towards those categories under their care, stating that such failure amounts to a denial of God's blessings and of His unceasing care for all His creatures.