Yes it's okay for adults to sleep with teddy bears.
There's no age limit for sleeping with a teddy bear or teddy bears or other plush toys that make you comfortable and help you sleep.
I'm in my 30's and I am a male and I sleep with my Teddy Bear every night and have slept my teddy bear since I was little.
I'm single and not married or have any kids but I love my teddy bears and cannot fall asleep without having a teddy bear close to me in bed.
I've been without my teddy bear before on a trip and I forgot to bring him with me but I could hardly get any sleep without him.
There are lots of adults both male and female that sleep with teddy bears and there's nothing wrong with it.
You don't have to give up your teddy bear just because you turn a certain age.