Agreed, it`s been there before and won`t go away. Although the reasons/causes are different for every husband, wife and relationship.
A husband who "does not want to lose her so he accepts her screwing around" would be the perfect description of a
wittol. i don`t see this type of cuckolding related to an adult lifestyle, at least not on his part, and the woman`s practice as cheating.
Speaking about the lifestyle... For some couples it is a husband`s sexual desire to see or know their wives "screw around". In many cases the wife would submit to his need and enter the lifestyle instead of choosing to do so (mainly) for her own pleasure/benefits.
For me my woman`s pleasure is the central interest for choosing such a lifestyle. For my lady it is enjoyment of some extra out-of-the-box sexy fun together. So, fortunately our likes match well for the kind of play we indulge in.