Sloppy seconds then doesn't even touch it.
actually, given a lot of the harem scenes i looked at, majority of the girls are pure.... so lore wise it'd count as you having their first in a way
belladonna is the only exception i seen so far, but everyone else i've seen out of my 45+ collected 1st scenes haven't had their first until then
Japanese Iris is a widow.
isn't queen of night a full blown hooker though? think i did read it somewhere she works in a brothel