Upon a trial for bigamy, it is not necessary to prove either of the marriages by the register, certificate or other record evidence thereof, but the same may be proved by such evidence as is admissible to prove a marriage in other cases, and when the second marriage took place out of the state, proof of that fact accompanied with proof of cohabitation thereafter in this state, is sufficient to sustain the charge. R.L.1910, § 5903.
Oklahoma Legal Code