Every "There’s Only One Answer" discourse and explanation is either plain wrong or useless.

Life is complex. Human beings are even more complex, and often contradictory (can you love someone and still cheat on him/her? Of course; many people do it).

Saying that "Life / Love is simple", means you simply don't understand it.

"For every complex problem there is an answer that is clear, simple and wrong." (H.L. Mencken)