I’ve seen a lot of people being silly about DnD talking about fucking your way into and out of bad situations but, if you look in the monster manual I think there’s strong support for the idea that half-orcs as a species are constantly horny
Orcs are constantly fucking and that’s why they have so many different types of half-orc offspring. So if your character has orc blood it actually makes sense
A species is formally defined as any group of creatures which can reproduce and produce fertile offspring. For example, a horse and a donkey can reproduce, but the resulting mule is infertile and thus a horse and a donkey are not the same species; same with things like ligers and zebroids. A chihuahua and a husky on the other hand are the same species because their puppy is a perfectly viable mutt. This rule gets bent when magic is involved, like with dragons or fiends/celestials or fey, but it’s solid through the races that have conventional biology.
Please note that a Gnome and a Halfling can technically reproduce, but they aren’t the same species and the resulting Gnomeling is kinda like a backwards mule: infertile, with most of the weakest traits of both parent species. Extremely sneaky though.
I’m amused by things like how a Dryad is magic enough to mix with anything except a lizardman. And a Sprite with a Giant is listed as a …Maybe.
Orcs, humans, and elves have a sort of special interaction. All three (and ogres) are the same species, technically, because their offspring are totally fertile without magic. Formal classification of these races is just based on percentage of each ancestry. In Human/Elf crosses, anything less than 50% elf blood is classified as a human (might have slightly pointed ears and live a little longer than average, but doesn’t get the full set of half-elf traits). 50-99% elf, with the remainder human, is classified as half-elf. Only 100% elven ancestry is actually considered an elf. Orcs and humans follow the same basic rule but in reverse; anybody with 51-100% orc blood is an orc, with 50% or less orcish blood and the remainder human being considered a half-orc (though depending on who you ask somebody who is 90% human and 10% orc might just be considered human; sources vary on that point). Orc/elf crosses have a lot less data to draw on, because almost nobody is willing to talk about them, but I know a 50:50 elf/orc split is classified as a half-orc, indistinguishable in capabilities from a human/orc split, so you could extrapolate from there that it follows the same rule as the other two binary combinations. The real question is what happens when, for example, a pure elf fucks a 50:50 human/orc cross? 50% elf blood is classified as half elf, but 25% orc blood is a half orc, right? Do you split the difference and end up with a weird human?