Правило 37 Василия Великого

He who has entered into marriage and is taken from him by someone else's wife will be accused of adultery for the first, but innocent of the other. (Trul. 87; Basil Vel. 21, 34, 39, 48, 58, 77). Someone else's wife (άλλοτρίαν, alienam) in this rule is either a woman bound by a legal marriage or a girl legally betrothed to someone 78. Whoever, therefore, commits adultery with such a άλλοτρίαν and by a legal sentence she will be taken from him - be she another man's wife or bride - and he, deprived of this concubine, enters into a legal marriage with a free, unmarried woman, then, according to this rule, such a person is subject to the penance prescribed for adulterers, only for cohabitation with someone else's wife or fiancée, but for cohabitation with a wife with whom he entered into a legal marriage, he is not subject to any punishment. However, the latter must be understood not in the sense of church marriage, but in the sense of cohabitation, which is discussed in the 26th rule of St. Basil, i.e. in the sense of concubinage, for if a legal church marriage were meant here, then the one who is guilty of adultery could, after widowhood, enter into a new marriage after having endured the entire fifteen-year (Basily the Great 58), or seven-year (Trul. 87) penance; if by his adultery he gave reason for the dissolution of the marriage, then he has no right to ever enter into a new marriage again (Basily the Great, 48). Interpretation of Balsamon in Af. Synth., IV, 181. You might be interested in: