Wet bone
A wet penis. When a male's penis gets dampened or moistened by masturbation, or sexual intercourse. Could be a result of vaginal or anal sex, or oral sex.
Dan's pre-ejaculate fluid became homogenized with Shelly's warm, sticky saliva. His tall erection was covered in a slippery, sticky, semi-thick, glistening sexual substance. Dan had a wet bone.
Tail Bone Wet
A very wet state of female arousal. To be Tail Bone Wet, a female is involved in sexual activity on her back and her state of sexual arousal and any moisteners make her so sloppy wet that her love juices overflow from the vagina, down her ass crack and dampen her lower back.
Roger had his girlfriend so turned on from all of the oral sex he was giving her that when he finally gave her the bone he reached around and grabbed hold of her ass checks and found her to be Tail Bone Wet.