When the man doesn't think it is, apparently according to this article
In my understanding, compelling a woman to have sex because she's your wife/girlfriend and therefore she should agree, is rape - and I believe this is now supported in UK law. The article seems to be saying that if there is no level of force, it's not rape. The writer asks "But is it clear from the question that we're talking about making someone have sex, or someone not consenting?". What exactly is the distinction?? Yet another journalist who thinks women's bodies belong to men.