Can you put a gate up? Try and explain to him or ask him why he wants to come in with you guys? He may need a night light, or a drink Etc

Our eldest did this around 3 yrs old (last year) we were told to just constantly return her to her bed. It took a few restless nights but she got it. If we gave in on any night but it sent us back to the beginning and she became more persistent as she wasn’t sure if this was the time we would give in. I say return him to bed and stay strong, don’t give in.

We had the same problem, all you need to do is when he gets in your bed, take him straight back to his own and tell him that the bed is too small and he needs to stay in his own bed. My son sometimes did not even remember getting into our bed so we think he would half wake and just an instant reaction to jump into ours. As long as you be firm and take him back to his then you will no longer have a problem.

You need to be firm. Close your door at night do that he can’t get in and assure him that big boys stay in their beds

Persevere with ensuring he goes back into his own bed! Play up the ‘Big Boy Bed’ scenario & perhaps implement a rewards system to assist!

just keep putting him back, eventually he will start to stay in his bed all night

Consistency is the key with most issues. Decide what you want and make sure that the whatever you choose to do it will result in getting what you want. Your the adult. Just keep taking your son back to his room as soon as he enters the room, or when you wake up with him getting in the bed. Keep taking him back to his room, not too much conversation as you don’t want him wide awake and say ie Michael’s bed is where Michael sleeps…stick at it, you may get relapses, but it will stop if you are consistent, don’t cave in once or you undo your good work….good luck and sweet dreams.

If having him in with you is something that you dont want then you need to stop it asap.
Of course he prefers being in with you but you need to simply put your foot down and say “NO”
Take him back to his room straight away and tell him that he is no longer allowed to sleep in your bed. OF course he will not understand why he was allowed to do this and now hes not so expect a few tantrum and for him to keep coming back into your room a million times but you need to not give in and stick to your guns and just keep taking him back to his room. It might take one night or it could take 2 weeks but he will finally get it and give up as long as you dont give in and allow him to sleep in your bed at any point.
You need to teach your children that when you say something you mean it.

I used to leave a hall light on. What about a night light.

all of my kids still come into my bed and I just pick them up and leave them there. To get them out of the habit you will need to take them back to their own bed when they come in