Teresa my wife wears my t shirts to bed during the summer months and during the colder times she actually wears what looks like men's woolen bottoms. I myself wear those lounging pants that are woolen sometimes when it's cold and my t shirts I bought just for bed time. My point is we don't have any pajamas we designate for sleep wear. We wear what's comfortable to us. The older I get the more comfy I like to be. I have even quit wearing ties to church but occasionally wear one to a funeral ( the older you are the more of those you will attend also). My suggestion just wear what you are comfortable wearing. I really don't know if I would sleep better in a gown or what I wear now. I doubt very seriously the thought of another woman wearing the gown will enter her head unless she reads what you wrote on here. Just do t bring it up. I don't worry about the small stuff until it happens then in your case I'd simply say ummm never thought of dear do you want me to change. Don't sweat it just do what you want and then ask for forgiveness for being so thoughtless about it.
I think very few of our wives really 100% enjoy what do anyway. The more I read on here the more I think that. Some are accepting but only to certain points and it seems very few don't have some restrictions on here.