Maybe it's not a bug. It's a feature. Like, combat Siegwulfe is so ugly that, compared to her, you look stunning. Thus, the increased sexiness. And vice versa with the bimbo version.
Oh, and the thing is still there, by the way. 0.9.029-PUBLIC#2748.
The numbers are still all over the place in 0.9.021-PUBLIC#2554. Can someone look into it?
I can attach a save file. You'll see that I have bimbo Siegwulfe equipped, but my sexiness is only 1.
According to combat statistics in the Codex:
combat Siegwulfe gives +5 sexiness (while she should only give bonus to evasion);
bimbo Siegwulfe doesn't give any sexiness;
and bimbo-domme Siegwulfe gives only +3 sexiness (in addition to evasion).
If the info from the wiki is correct, either she is...