To me it seems that the current relationship can at best be called a live in relationship, if all the criteria for that are met. If not, then the relationship is of a much lesser seriousness. Isn’t a live in relationship based on no commitments whatsoever..it may someday lead to marriage or there may be discussions, even a serious discussions, about marriage but unless that happens I guess both partners are free to look here and there. However, if it is found that one partner is in touch with another person after marriage then yes, it qualifies for a serious consideration to stay in relationship or not, but as of now?