It is so easy to do this - and many BT devices will just connect with whatever they paired with last time. This happens about a tenth of a second after you have disconnected them !
I have a cheap set of BT earphones and mic and they are there so that I can test things out while sitting at my desk, rather than freezing my bits off in a cold garage, flattening the bike's battery. And I always remind myself that I must disconnect my GLINBT18 earphones from the XT and pair it with my BTM03 which the BT device that plugs into my wired intercom. Do I remember ? Hardly ever.