そろそろ帰らないと、家族が心配するよ。

Pronunciation: Sorosoro kaeranai to, kazoku ga shinpai suru yo.

Meaning: I should head home soon, or my family will start worrying.

This phrase uses 「そろそろ」(sorosoro) meaning "soon/gradually" and 「～ないと」expressing necessity. It's a natural, polite way to excuse yourself from social situations in Japanese culture, where consideration for family is highly valued.