How much can dogs know about context – sleeping on bed

Hi all! So it’s gotten to the point where having my dog on my bed is causing sleep issues for my girlfriend. So, clearly, time to train my boy to sleep on his bed through the night. (He will sneak up onto the bed after we’re asleep.)

I’ve read the posts and responses on how to train a dog off the bed, and they’re helpful. Fingers crossed

But there are couple of complications here…. Why I’m posting. First, her dog (who is much smaller) always sleeps with her. That’s highly unlikely to change regardless of what I do with my dog.

Second, when the gf is not there, my dog often prefers to not sleep in the bed with me. He likes to be on his bed or out of the bedroom entirely.

Basically, I realize I need to be trained as much as my dog here, but looking for advice on what rules to implement and some best practices. Thank you all!