My wife and I have been married for over 35 years and are still sexually active. For the past year or so I have wanted my wife to spank me as a form of foreplay. She has done it a few times but is not real crazy about it. I like her to pretend I have done something to deserve it and then have it be like punishment. I even have talked her into having me put on some of her thong panties and then spank me. Is this totally weird, or a somewhat normal change that can come with age?