I still do at times, but it is becoming humiliating.
Then stop. Do not beg. You are worth more than that.
If he wasn't sharing your bed, would you be going out to find another lover? Back when I was a kid it was no big deal to have to share a bed. Heck in my Mom's day if a beau came to visit and needed to stay b/c of distance they still stitched them into the bed (no extras with 9 kids and usually 3 to a bed). I know it was a different time. I know how badly you want the affection. It's a decision you have to come to yourself. What will work for you? What do you think would happen if you asked him to sleep somewhere else? I hear the fear in your words. Let it out here.
I understand about telling the kids and raising alarms, but they probably already (each in their own way) know something is up.
I don't have the answers for you. If I did I would have used them myself.