Teh NIH.gov is thexy:
Casual or anonymous sex can provide sexual gratification without the complications of a relationship
http://www.pubmedcentral.nih.gov/art...dd50.0x9a020a8
"Lesbians may choose to be a “penetrator” in lovemaking by using a dildo and harness or other sex toys"
http://www.pubmedcentral.nih.gov/art...dd50.0x9a01f48
"A self retaining “butt plug,” which can be used in anal dilatation exercises or simply as a sex toy"
http://www.pubmedcentral.nih.gov/art...dd50.0x9a0d198
All sorts of sexual perversion to be found on the NIH's site. I'm glad to see the government finally disseminating information about anonymous sex, strapons, and butt plugs.