There is no maximal decidable expansion of the $⟨\mathbb{N},\{<\}⟩$ structure

We are going to prove that if the theory of a structure $\mathcal M=\langle $\mathbb{N}$, \Sigma \rangle$isdecidableandthestandardorder$<$ on natural numbers $\mathbb{N}$ is definable in $\mathcal{M}$, then there is a nontrivial decidable expansion of $\mathcal{M}$