A "love triangle" is a situation where three people are involved in a romantic relationship or have feelings for each other. It usually leads to conflict or tension because one person may be torn between two others. Full definition
An added layer to the plot was a very weird love triangle between the agents, although, truth be told, this was not necessarily a bad thing. (thecriticalcritics.com)
If I look, most of my books include some form of love triangle, because it just makes for such a great story. (bookpage.com)
The film looked ok in the beginning talking about aliens etc and then it just fell into this terribly boring love triangle story. (mediamikes.com)