At what point does honesty become cruel to the listener?

To My Dearly Beloved Friends,
Ian loves me, and I love Ian. However, the time I have known Ian and the circumstances under which I have known him makes me less likely to want to date him.

I cried to Ian again last night, over Matt. I am still being wrecked continually by the Matt situation.

To be honest, that was not my intention. I had called because I was homesick, but Ian was all too busy to talk to me, which is fine, so I called Matt. I had not even realized that Matt had called/emailed me because I have been so busy, so he thought I was just calling him back, but I was calling him just to talk.

I love Matt and he just does not get it and continues to play with my heart, perhaps unintentionally.

But the question on the table is- Is it cruel to speak of another man to someone who obviously cares about you, despite the fact that you want to be as honest with them as possible?

-Nat

PS. My roommate is awesome, I just thought you should know.

PPS It hurts to breathe because I worked my abs so much this morning.