According to the UK courts, it actually precisely rape: http://www.bailii.org/ew/cases/Misc/2011/5.html http://www.bailii.org/ew/cases/Misc/2011/5.html Basica

According to the UK courts, it actually precisely rape: http://www.bailii.org/ew/cases/Misc/2011/5.html http://www.bailii.org/ew/cases/Misc/2011/5.html Basically, rape is defined as penetration, without consent, and without a reasonable belief in consent. Someone who is sleeping cannot consent, and you cannot therefore have a reasonable belief in that person's consent (if you're aware they're asleep, at any rate). Thus under UK law, an allegation of penetration of a sleeping person is an allegation of rape. (The law is the same in most US states, Canada, Australia, Scotland, NZ, and many, but not all, European countries. Even places where it doesn't count as rape, it's generally a serious crime. In Germany that would amount to an allegation of "abuse of persons unable to resist", which can carry a stiff penalty.)