What happens when you specifically ask for sex somewhere other than the bed?
We make jokes about doing it other places but it just never happens
From reading your comment I’d say take control and lead him into another room. Act on it. If he’s not going to do it and you want to do it, then do it. If he then still doesn’t want to do it there then perhaps the bed is where he is most comfortable at? I doubt he wouldn’t want to as you said he even jokes about it. And I’d converse with him about what you want and tease him saying you’ll wear sexy clothes or something
You kind of have to get creative with kids in the house if you don’t want it in bed. I’m absolutely terrified of a kid waking up and coming out to catch us so we stick to our room but that doesn’t mean you have to use the bed