Hello, Ema2two.
Thank you for being a part of the Apple Support Communities. We’re happy to help with your Apple Watch questions! It sounds like you’re wanting to pair your watch with the iPhone that you’re using at that moment, and you’re wondering if this is feasible.
This is a tough question. Technically, you can unpair and pair your Apple Watch as many times as you want; however, it is designed to be used with one iPhone in that many of its features sync with the Apple ID / iCloud account. When you unpair it, it essentially erases the watch, and data is restored when paired with the same device again.
If you want to see if unpairing and pairing works for you, you might run a week/weekend trial. Pair your Apple Watch to your work iPhone Sunday evening and wear it throughout the week at work, then pair it with your personal iPhone on Friday evening for the weekend. Any data that syncs while connected to your work iPhone will only be available when paired with that device, and vice versa.
This article will help:
How to pair your Apple Watch with a new iPhone - Apple Support
Warmest Regards.