Gerontophilia
Gerontophilia is sexual attraction to much older people — specifically the genuinely elderly, well beyond the 'MILF' or 'cougar' range. Where those focus on mature but middle-aged partners, gerontophilia is about the truly old: grey hair, wrinkled skin, and the signs of age others avoid. Some are drawn to the look and feel, others to the experience, tenderness, or authority an elder represents, and some to the taboo. As always, it's about consenting adults. It can be a real partner preference or an age-gap roleplay fantasy.
The appeal varies — genuine attraction to aged bodies and their textures, a draw to the wisdom, care, or authority of an elder, a nurturing or being-nurtured dynamic, or the taboo of desiring someone society desexualizes. For some, the large age gap itself is the charge.
It may be a sincere attraction pursued with an older partner, or a roleplay where one plays a much older figure (a 'GILF,' an elder authority) through dress, manner, and scenario. Age-gap power dynamics often flavour the scene.
Between consenting adults it's low-risk. Be mindful of any real health or mobility considerations with an elderly partner, and — as with all age-gap dynamics — ensure genuine, un-pressured consent and equal footing.