On-again, off-again relationship
An on-again, off-again relationship (otherwise known as an on-off relationship, on and off relationship, or similar) is a form of personal relationship, between two people. They may wish to keep an ongoing, formal relationship but have difficulty doing so because of continuous conflicts between themselves.
Reasons for such relationships to form can be complex. Such reasons can involve things which are directly internal to the relationship, or external factors, which may or may not be within their direct control.
The couple may not be able to live or associate with each other for physical reasons (e.g. they live in different places), or for emotional reasons (e.g. they cannot relate to each other outside of a physical relationship, perhaps sharing little in common).
Additionally, the relationship may be confused by opposing outside influences. These may be things such as current relationships with others outside of the couple concerned relationship, or the disapproval of other people. They can also involve cultural reasons, such as legality in some countries of non-marital or adulterous, extra-marital, relationships, especially those outside of typical monogamous relationships such as marriage.
Sometimes when couples breakup, one member of the relationship may regress to their former partner for comfort after a period of time. Despite relationship issues that may trigger a periodic hiatus, "on-again, off-again" couples often continue to reunite out of a persistent hope that the moments of happiness and gratification they have known will eventually constitute the entire relationship.