Is it permissible for a woman to caress her husband's penis with her foot or to hold it with the intention of fondling and caressing, while the husband enjoys that?

Enjoyment between spouses is permissible in all forms, except for anal intercourse or vaginal intercourse during menstruation or post-childbirth bleeding (nifas). There is no objection to the foreplay mentioned, whether it is intended for the enjoyment of one spouse or both, or if nothing is intended from it at all.