" Hello ... "

So you've planned, it you'll do it, over phone.
There's no harm in it, it's completely fine.
I mean you know it's legit in the path of finding happiness and true love, right ?
The guy, the one who loved you more than anything else in this entire existence deserves it, Yes !?
Girl, you think you'll give a goddamned lame fucking reason, that why this relationship ain't working anymore like it did few months back. Think of it, you can.
You'll simply call him up in a random evening, waking him up after his lazy afternoon sleep, the fact that his heart still skips a beat when he hears his special ringtone set for you, the big full screen caller ID along with some cute nickname makes him as happy as he was perfectly a year and six months ago, when you called him for the first time, will be of no value. As you have made up your mind, of parting ways, finally. Hush.
He'll receive, and as you've planned, you'll just say

 " Hello ! It's over. Am sorry. "

and hang up. Congratulations girl, you executed perfectly what you planned.
You'll be a bit sad, for a few days. And that's legit. We get sad when our cookie packet finishes too, right ? All things come to an end. May not be, good, but it does.
After all, a year and six months is not very long time, you two were just committed. It's not that, you both have been married for years or stuff, but a year and six months of relationship can be ended, in just a few seconds, it's nothing wrong.
The next morning you wake up, call the new guy who was your new " to be husband ", text him with Good Morning texts and love quotes. You're ready to face your past, as you had planned for this day for months.
The fact, that he was crying the entire night, his eyes are too sore and red to look up the clear sky will not bother you much, because this new guy is more important than he was.
In a week you'll forget everything, all the memories and you've started making new ones too.
Congratulations, you did it. You just broke a heart. There's no harm in it, it's completely fine.
I mean you know it's legit in the path of finding happiness and true love, right ?
The guy, the one who loved you more than anything else in this entire existence deserves it, Yes !?
You think, he'll move on like you did. Start thinking about the future now, because according to you, you both finished yesterday evening, everything you had for each other. He'll slowly gain control of his emotions back, or maybe plead in front of you, kneeling, cying his heart out.
But, according to you, it had to happen right ? Sooner or later ? And one year and six months is not a very long time. Duh ?
You'll eventually pay no attention to his drama, and continue walking with the new guy, holding his hand. It's fine right ? To find the correct guy, you may have to break a heart or two ???
But, the reality is, he would take a few days to understand what happened with him, to come out of the state of trauma. He needs people to consolidate him, that " Boy, it's over, she ain't your's anymore ". Moving on, is like light years away for him, he just wants you back. But it's completely fine, you had to do it ? Right ??? Today or some other day.

So girl, I just want to congratulate you on your new happy life, and the fact that you've finally found The Man of your dreams, the Knight in shining armour, the Alpha male ? Right ?
He was an asshole loser anyway, he knew nothing, just knew how to love you, and love doesn't fetch bread, right ?? You completely did the right thing. No second thoughts.

But girl, some random beautiful evening after a few years, when your Ex. will finally move on, forget the old memories, heal up, and maybe settled with someone else. After your beloved afternoon sleep, when you'll be least expecting it. 

You'll receive a call too.

" Hello ! ... "