Television sets should come equipped with a box of Kleenex tomorrow night, thanks to a pair of finales that will undoubtedly yank on heart strings across the country.

First, Private Practice will bid farewell forever with a wedding six years in the making.

Then, Parenthood Season 4 will draw to a close with "Because You're My Sister," as Jasmine and Crosby receive exciting news; Kristina readies for the next phase of her treatment; Drew learns about his college applications; Amber and Ryan focus on the future; and Sarah must choose between Mark and Hank.

Watch the official NBC teaser now and, seriously, get those tissues ready...

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.