Okashikute, minna, sanjuppun warai-ppanashi datta. (It was so funny, everyone laughed for half an hour.)
Situation 1: Takako talks to her high school classmate Chika about a program she saw on TV the day before.
知佳： うん、見た見た！おかしくて、家族みんな、 30分笑いっぱなしだった。
Takako: Kinō no komedii omoshirokatta yo. Mita?
Chika: Un, mita mita! Okashikute, kazoku minna, sanjuppun warai-ppanashi datta.
Takako: Yesterday’s comedy (show) was funny. Did you see it?
Chika: Yeah, I saw it! It was so funny, everyone in my family laughed for half an hour.
The verb 放(はな)す means to let go or let loose, but you may also recognize its masu-stem form, 放し, attached to the ends of various verbs in their masu-stem forms (X). This mix expresses the notion that X continues or repeats for a certain period of time and is usually used colloquially as Xっぱなし. In Situation 1, Chika is telling Takako that her family was laughing for 30 minutes straight, 笑(わら)いっぱなし. Other examples include:
電車（でんしゃ）が込（こ）んでいて、1時間（いちじかん）立（た）ちっぱなしだった。 (I had to stand for an hour straight because the train was so crowded.)
うちの高校（こうこう）の野球部(やきゅうぶ）は、8年間（はちねんかん）負（ま）けっぱなしだ。(Our high school baseball team has lost for eight years [hasn’t won in eight years].)
Situation 2: At home, Mrs. Okubo chides her daughter for leaving the refrigerator door open.
Haha: Mariko, reizōko no doa ga ake-ppanashi datta wa yo. Sakki, nomimono o dashita toki, shime-wasureta-n-desho? Ki o tsukenai to.
Mother: Mariko, the refrigerator door was left open. When you took a drink from it earlier, you forgot to close it, correct? You should be careful.
Depending on the nature of the verb (X), the Xっぱなし structure can mean something different. In Situation 2, Mrs. Okubo uses it with the verb 開（あ）ける (to open) to indicate that the refrigerator door was left open, 開けっぱなし. In this case, Xっぱなし indicates the result of an action in which something has been left in an improper state:
おじいちゃんの家(いえ)は、いつもふとんが敷(し)きっぱなしで不潔(ふけつ)だから、心配(しんぱい)だ。 (Grandpa always leaves his futon out at his house, and it’s unclean so I’m worried.)
For a more neutral nuance, use a verb in its ta-form and add mama instead: 昨夜(さくや)は暑(あつ)かったので、窓(まど)を開けたまま寝(ね)た。 (As it was hot last night, I left the windows open and slept.)
Bonus Dialogue: Mr. Okubo comes home and finds his wife lying on the sofa.
Husband: I’m home! Oh, what’s wrong?
Wife: I’ve been working nonstop since this morning, I’m exhausted.
Husband: What made you so busy?
Wife: Mariko did her homework in a panic this morning, left it on the table and went to school without it, so I had to run after her. Then I had to clear the breakfast, clean up and do the washing. As soon as I finished, the kids returned home one after the other, kicked off their shoes, dropped their bags and left them lying around.
Husband: You should have made them put them away neatly by themselves.
Wife: I wish! That doesn’t work. Mariko immediately goes out to play, Mitsuo’s got cram school and Takako heads to her piano lesson. In the end, it’s my job to tidy up after all of them!
Husband: Thanks for all your hard work, though. I’ll try not to bother you as much as possible.
Wife: Thanks. However, while you were saying that, you took off your socks and tossed them (on the floor). Please pick them up right away.