Is love and monogamy a biological reality?

Is love and monogamy a biological reality?

What is love? Sounds so corny to ask or even to ponder. But we must do as human do and, we do love. What is monogamy? Simple answer the exclusive union of two human beings. Now keep in mind we are the only species on earth that subscribes to this thought, and understandably so.
When it comes to both questions I have an observation and a question of my own.
My Question is?
Is it possible for a man to cheat on his wife , lie to her to cover up his affair, yet still love her enough to die or kill for, can both statements be true. Conversely is it also possible that a man can be faithful for all his relationship, yet distant, cold and has beat his wife, but has never cheated?

I realize these are hypothetical extreme examples and that imo if a man beats his wife he would also cheat on her. But the first questions is legitimate and if fact if this situation is a reality then I am open to other questions about monogamy, especially in men.