My partner doesn't put their phone down for a second, should I be worried?

It depends on the context, honestly. If she's constantly scrolling social media or playing games, that's one thing, but a lot of people need their phone for work or just like staying connected. What matters more is whether she actually puts it down when you're together or pays attention when you talk to her. If she's ignoring important conversations, plans you're making, or straight-up leaving you out because she's on her phone, then yeah, it'd be worth having a calm conversation about screen time as a couple.

Sometimes having your phone glued to your hand is just a habit, but if your partner obsessively checks it, hides it, or gets nervous when you see it, that's when something's off. My sister was doing exactly the same thing for a while - phone in her hand all day, slept with it right next to her - and it turned out she was in some social media group where she'd spend hours scrolling. When she admitted it, it was because she'd started ignoring everything else, including plans they had together.

What I'd tell you is to pay attention to whether there's a shift in behavior: wasn't she like this before? Does she ignore you when you're together? Is there secrecy around it? That matters way more than the phone itself. If everything's good between you two and she just has the habit of keeping it close, then honestly there's probably nothing to worry about.