Aren’t succubi and incubi technically the same creature, taking a man’s “seed” and then delivering it elsewhere, as a bullshit way to explain out of wedlock pregnancies?
No idea if dnd succubi follow the same rules. But there’s precedent for them to bat for the other team.
IIRC (w/o searching online), incubi are the male counterparts to succubi, and impregnate human females with demonic spawn, vs feed on "sexual energy" as succubi do. (I don't believe succubi are restricted to gender in doing so.)
Secondly, you missed the chance for "out of warlock pregnancies". ☝🏽💡