Or is the problem for him: that he doesn't want to enjoy your feet?

If so, that's his problem, or not if he accepts your will and decision.

Now, if you're saying you want him to enjoy a foot behavior, perhaps you will succeed with practice. You might institute some training that will gradually reward him for his behavior .... so he will choose it for the reward it may gain him ....

And if he still doesn't care for it, like Mobius implied: Do you Really care?