How to stop him getting in our bed?

[Eleast]

I have a soon to be three year old who is getting up every night to get in our bed, we have a one year old so crying it out can be a bit tricky and make matters a lot worse. He’s woke in the night for a while now but in September my husband was in hospital for two nights which really threw him off (he reacted the same when I was away overnight having his brother!) and then the same week we had a stomach bug go through the house. He got poorly and wanted cuddles in the night which was fine but then he cottoned on that saying he had a poorly belly meant he could sleep in our bed. We said he could sleep in our room but on the floor (we put an extra thick folded duvet for him to lie on with pillow and blanket & he always wants to sleep on his bedroom floor). Well it worked for a while and then it went back to getting in our bed and has done so for nearly two months now.
It’s not a habit I want him to get into plus he kicks and wriggles a lot in his sleep which means we don’t sleep too great either, and my LO is up at 5am so I’m exhausted. I just don’t know what to do going forward. I don’t think it’s night terrors as he goes straight to sleep in our bed, I don’t know if it’s some sort of separation anxiety
Any advice.

I'd probably say that daddy snores too loudly for him to be in there, and return him immediately every time. It stay with him and comfort him in his room until he's asleep or happy for you to leave.

I'd also take him out and let him choose some new bedding for his own bed, which may help a bit

At that age I would do Rapid Return.

Turn toddler straight back around and back to bed in a kind, but firm and no-negotiation kind of way. Just keep taking back to bed over and over and over again.

My children never got into my bed. Everyone sleeps in their own bed is the rule. Watch in the night garden episodes where upsy daisy doesn't like it when the others get into her bed.
But you have to be consistent, sore tummy doesn't mean sleeping in someone's else's bed.
Make a big fuss of how grown up he is sleeping in own bed, gets a sticker in morning etc