Ma malakat aymanykum, wrongly translated as "right hand" posession has nothing to do with slavery or fornication, as ill prove using the Quran.
-Prisoners of war = Asraa or asira (plural) 8:67,76:8
-Slave = Abdan (Mamluka) 16:75,24:32,2:221, imaakum 24:32 or ammah (singular) 2:221, abid to mean slave(s) of Allah
-YOUR OATHS = Aymanikum 2:224,225,5:89,16:92,94,66:2 THEIR OATHS = Aymanihim 5:108,6:109,16:38,24:53,35:42
-right hand = Maimanah 56:8,90:18 or Yamin 17:71,20:17,56:27,38:90-91,74:39
the Quran NEVER EVER uses the word AYMANIKUM to refer to the RIGHT HANDS but always and exclusively for YOUR OATHS.
Ma Malakat aymanikum (lit. "whom your oaths posess" wrongly translated as right hand possession) is a phrase used for the poor humans whom an oath has been pledged to be taken care of. They are not necessarly prisonners of wars but can be if one wishes to take under his special care (under oath) a war prisonner, ie raising his/her status.
In 33:50, the prophet is told that among the categories of women lawful for marriage are Ma Malakat yaminuka (singular) FROM AMONG the prisonners of wars, which proves they are a seperate group from war prisonners. Further in 33:55, the prophet's wives are not blamed for not wearing the veil in the presence of certain groups, including Ma Malakat aymanikum and this again excludes regular war prisonners. Or in 24:58 setting the limits of privacy inside a home between an adult and the rest of his/her household, including Ma Malakat aymanikum who cannot logically be war prisonners. In the context of marriage, they are also mentionned seperately than regular male/female slaves 24:32-33.
Ma malakat aymanikum are therefore some special people in society, weak and unable to provide for themselves. They might have families but are very poor to take care of them, Islam encourages a wealthy/capable believer to take them under his/her wing through an oath that he/she will provide for them.
16:71,4:33,24:33 remind the people of the moral obligation of sharing from what Allah has given them with the weak and poor, including Ma Malakat aymanikum. Then 4:36 clearly explains that the oath takers must provide Ma Malakat aymanikum i.e. those poor humans in our care under oath, equitably with everyone else "And serve Allah and do not associate any thing with Him and be good to the parents and to the near of kin and the orphans and the needy and the neighbour of (your) kin and the alien neighbour, and the companion in a journey and the wayfarer and Ma Malakat aymanikum; surely Allah does not love him who is proud, boastful".
No sexual relation (fornication) is allowed with them outside of wedlock 4:3,24:33.
This is emphasized again in 4:25"And whoever among you has not within his power ampleness of means to marry free believing women, then (he may marry) ma malakat aymanikum from among your believing fatayaat (young women); and Allah knows best your faith: you are (sprung) the one from the other; so marry them with the permission of their masters (ahlihuna), and give them their dowries justly, they being chaste, not fornicating, nor receiving paramours; and when they are taken in marriage, then if they are guilty of indecency, they shall suffer half the punishment which is (inflicted) upon free women. This is for him among you who fears falling into evil; and that you abstain is better for you, and Allah is Forgiving, Merciful", the believer is told to marry Ma Malakat aymanikum if he cannot sustain a free (financially) believing woman, and he has to take the consent of her family (ahlihuna wrongly translated as masters or owners). Ma Malakat aymanikum must be given their dowries justly and in case they commit an indecency they will have half the punishment of the self sustained women, and if one abstains from punishement altogether and is patient with them it is better, due to their past hardships that may have affected their common sense and judgement.