Toddler won’t stay in his bed - driving me crazy!

[Tiredmumoftwo2]

Please does anyone having any helpful tips because I think I might start to have a little sob on this.
DS 3.5yo bless him has always been an amazing sleeper! It’s been bliss. He now has an 8mo sister who is a complete sleep thief, but we’re dealing with that separately!
Since Christmas ‘22 just gone, I cannot get my 3.5yo out of my bed at night!
My husband’s family came to stay and they stayed in his room for 2.5 weeks and slept in his bed so he stayed in with us, which we thought was cute and lovely at the time and he had a ball. He has stayed in our bed sporadically before when ill etc but never for too many nights in a row. However since Christmas every single night without fail by 10pm he’s creeped into our bed and no matter how many times we try to put him back, he’s a persistent little thing. Because of lack of sleep from DD sleep thief, we haven’t really put up much of a fight with him, because we all need to get some sleep.
DD is getting slightly better now with her sleep and we’ve got more time to focus on toddler with this issue but I’m at a loss.
I’ve tried reward charts, promises of chocolate treats, I’ve played hard ball some nights but he’s still in with us by midnight, we’ve tried staying in with him which is fine as he has a small double but not ideal for us.
Husband and I are obviously distinctly lacking in intimacy or in fact pretty much any alone time at all because of all of this and I just want some time to myself back.
Thanks if you’ve stuck with me this long, looking for anyone’s miraculous ideas?!

Look up the Supernanny stay in bed technique. Think this situation would apply!

Can someone sleep in his room with him for a while, to get him used to staying in there?

We had this with one of ours. I walked him back to his own bed every single time, even if by the time I was back in bed, he had appeared again. Every time. One night it was over 80 times until he stayed put in his bed. This went on for about 4/5 days and I was a complete zombie. But it gradually tailed off, and a week later he had stopped. The only trauma was to me, I was sooooo tired, he just giggled and chatted his way through it.

Agree with @ilovemyslippers. Keep walking or carrying him back every single time. Keep it incredibly boring. Same phrase every time e.g “time to go back to bed, love you.” And that’s all you say. You’ve given him reassurance that you love him but by keeping it very boring and repetitive it’ll discourage him from continuing (as long as you’re persistent)