What's the hardest part of leaving a person?

If you must really break up, it is best to do it without breaking their heart because you want to be able to always have them as a freind. You don't want to be that one person that makes them treat other women wrong. If you really did do something to break this persons heart and they don't know it, try not to tell them the exact details unless you must. Treat the person the way you want to be treated. Tread lightly and be as truthful as you can.

...realizing you want him back in your arms again.

For me in my current relationship the hardest parts would be taking my son away from his father. And knowing that my husband who is already depressed would just sink into a deeper depression.

for me the hardest part is laeving itself... in any kinds of relationship... we invest time, love, give a piece of ourselves so we know that its never easy giving up someone...