Real Talk - Is Loyalty Compulsory In Any Relationship?

Okay so let me phrase this question in another way that would help define what loyalty personally means to you.

"Should or Would you tell a girl or guy, that you have feelings or like him/her, while in a relationship with another?

Would it be okay to "catch feelings" for another while with another?

Or in simple terms, are you of the opinion that  loyalty is key in any relationship?

And if loyalty is key in your relationship, why?

Scenarios:

A school of thought on relationship as "boyfriend/girlfriend" can say "ah well, nobody owes anybody anything as long as it's not marriage or as long as marriage isn't the goal of that relationship or when it's not like relationship is a prison sentence",

Do you agree?

Or would you say "well, it's not like I can control my feelings so....." 

Last Words -

In essence, should loyalty be regarded as a VALUE everyone should have, or should it be limited to certain circumstances? 

Is it a staple in every type of relationship (friendship, family,business)

Looking forward to reading from you as always!

Xx..

Image culled from Google