Based on 120 niche photos. It's not great, maybe I'll redo it sometime, seems to give a reasonable result for 1 in 8 renditions. My workflow is to generate the image using an anime model for flexibility of composition, then switch to a semi-realistic model at 20%. Finally I scale-up with the same anime model for 20% and refine with a realistic one.

Results are very dependent on the models used so try around, don't write it off if you end up with teddybear on teddybear action, or some hybrid girl-bear.

Recommend keyword (tb1:1.1), anything else is for your experimentation.

1girl, (stuffed toy:1.3), (stuffed animal:1.3), (teddy bear:1.1), (nude:0.7), bed, indoors, solo, hug, bed, barefoot, long hair, lying, breasts, nightdress, (sex with teddy bear:1.1), (1boy:1.2), (best iality:1.3), female masturbation, dark-skinned female, (hetero:1.2), lingerie, pussy, looking down, arousal, aroused, orgasm, looking pleasured, dildo, sex toy, oral, fellatio, lingerie, straddling, girl on top, sex, vaginal,

Try putting animal ears, bear ears, fake ears etc. in the negative prompt to avoid a furry female.

If you get good results, I'd appreciate your posts, thanks