Can I get married without the witnesses or any other marriage formalities?

I want to marry a boy whom i love but i don't have any chance to go out and marry him officially or marry him through other marriage formalities... Like, we both have high sexual urges and we want to fulfill it at a halal way without any third witness... Will our marriage be acceptable if we tell ourselves that we are husband and wife by promising to Allah, and also the groom will gift paid money as delmohor? if its not then please tell me a way out