Dialogue: #1

小明 (Xiǎo Míng): 今天我准备去跑步，天气很好。(Jīntiān wǒ zhǔnbèi qù pǎobù, tiānqì hěn hǎo.)

小丽 (Xiǎo Lì): 可是偏偏下雨了，真不巧。(Kěshì piānpiān xiàyǔle, zhēn bù qiǎo.)

小明 (Xiǎo Míng): 我也没想到，真是的！(Wǒ yě méi xiǎngdào, zhēn shì de!)

小丽 (Xiǎo Lì): 偏偏遇到这种情况，真是倒霉。(Piānpiān yù dào zhè zhǒng qíngkuàng, zhēn shì dǎoméi.)

The expression 偏偏 is used to express something happening contrary to what was expected, often with a sense of irony or frustration.

Dialogue #2:

小明 (Xiǎo Míng): 我今天准备好好休息。(Wǒ jīntiān zhǔnbèi hǎo hǎo xiūxí.)

小丽 (Xiǎo Lì): 偏偏你现在有工作要做？(Piānpiān nǐ xiànzài yǒu gōngzuò yào zuò?)

小明 (Xiǎo Míng): 对啊，老板偏偏在最后一刻才给我任务。(Duì a, lǎobǎn piānpiān zài zuìhòu yī kè cái gěi wǒ rènwù.)

小丽 (Xiǎo Lì): 真是太倒霉了！(Zhēn shì tài dǎoméi le!)

In this context, 偏偏 expresses the idea that something happened in a frustrating or unexpected way, as the boss gave the task at the last moment.