Memnoch
Only by someone who doesn't know what rape is.
The issue is not sincerity but consent. If both parties consent then it's not rape, end of. The only exception is when someone is deemed legally incompetent to give consent, e.g. a minor, then it's rape..
If you give someone a loan of a 1000 and they promise to pay you back but fail to do so is that theft?

You freely gave them the money.