Search Results: platonic friends romantic relationship

Let's say there's a person 'A' in exclusive romantic relationship with person 'B' for many years.

Meanwhile 'A' gets to know a person named 'C' (they are of opposite sex) and soon they become best friends.

'B' is not comfortable with the close friendship between 'A' and 'C' but tries to be understanding and hence asks 'A' that he/she wants to meet 'C' - to get to know him/her better. But 'A' deines and says it'll be awkward and that 'C' won't like it. Even 'C' denies meeting 'B' and says he/she doesn't feel comfortable with the idea.

'A' always seems to be spending more time with 'C' as compared to 'B'. This creates a downward spiral in relationship between 'A' and 'B' and lots of other issues. 'A' and 'B's relationship becomes toxic over time. 'A' brings up the fact that he/she's not comfortable with their friendship many times over a period of time but 'B' always reassures 'A' that it is only platonic and nothing more. Somehow they remain committed to each other.

Finally one day (after about a year) 'A' and 'C' fall in love with each other. Both 'A' and 'C' express their love for each other verbally (nothing physical) after realizing that they both are deeply in love with each other. 'B' is still unaware of this fact at this point.

A few days later 'A' decides to reveal this to 'B' - though nothing physical happened between A and C till this point. Finally, 'A' and 'C' get into exclusive romantic relationship with each other.

Is it normal for 'A' and 'C' to fall in love with each other? Is it cheating? Is anyone faulty here at all? What's your best judgement about this situation?