Eyebrows
As a 61yo male, I say, this is an GOOD QUESTION. I hope those in the scientific community with PHds do a scientific study and write a paper on this. :)
I've always had the though that ladies with hairy arms (light hairs or dark) were always better in bed. I remember someone telling me this about 15 years ago and to be honest it been true every time. Also another, red on the head, great in the bed. Redheads do have more fun, and in my experience, are more prone to iking anal
I can vouch for the redhead comment. My wife is a redhead and she’s crazy horny. She loves anal just as much as she loves her pussy fucked. She is always down to give me a BJ. My wife has nice eyebrows, not thick ones but she has a bush. She used to shave her pubes off but after our first child she stopped shaving and I told her I liked the bush. So she’s had it ever since. Well she get a bikini wax still. I consider myself a lucky guy. We are in our 40s with 3 kids and our sex life is still as good today as it was when we first met each other when we were in college.