N.H. Rev. Stat. Ann. § 457:41
In actions for criminal conversation, and in indictments for bigamy and the like, there must be proof of a marriage in fact.
Source. GS 161:18. GL 180:18. PS 174:17. PL 286:38. RL 338:41. 2014, 44:3, eff. Jan. 1, 2015.