You never get used to it.

Letting a child cry themselves to sleep is always trying. Even if you find a way to distract yourself there is a sort of tension that won't ease until they stop crying. Once you realize that it is over and probably will not start up again it is like realizing that you have been holding your breath and a palpable wave of relief washes over you. No matter how many years or how many children you have made it through you are never used to it.
I let Levi cry himself to sleep tonight because he was so tired and wouldn't let himself go to sleep. I usually just let him do whatever he wants in the evening because it is just me and him and as long as he isn't fussy I see no reason to make him go to sleep before he gets picked up by his mom, but tonight I had Dono as well. Dono is not a problem but he riles Nathan up and is one more munchkin running around the house. So Levi was being fussy and I had my hands full with the other two so I decided that it was time to be the mean aunt and to make him get the sleep that he didn't want. I was surprised it only took 20 min. or so but I still felt like a cad. When I got him out of the crib to go home he had a super wet diaper and I felt even worse but he smiled at me as I changed him and I just melted my heart. You never get over it.