strange foot worship

I have been living with my sister, her husband, and their four children for a number of years.
I'm the godmother of their youngest four years old child boy to whom I have always shown affection and given love. He has always pretended I was his mother although he knows it's not true since we show him pictures of his mother pregnant with him and explain it to him. Sometimes he behaves or expresses feelings of possessiveness towards me, and lately I have been facing a problem that I don't know how to solve.
For the few past months he has developped a strong fixation on my feet. As soon as I come home from work he wants me to take off my shoes so he can put both my feet on his cheeks where he keeps them in a strong grip.
When I'm in the bathtub he comes in and just sits on a chair and keeps looking at my feet, totally mesmerized. If I don't let him in the bathroom he waits for me outside and asks to behold them as soon as I'm out of the shower. In the evening when we're all watching TV, he sits and plays with my feet for hours.
Many times his father has told him to stop with no effect. I feel very uncomfortable about this situation ; I often wear socks to escape his invasive habit. I want him to stop but I don't know what to say to a four years old boy without hurting him. Besides I wish I knew the meaning of his ambiguous behaviour so I can have a constructive dialogue that will eventually make him stop doing it.
Is it a sexual deviance ? Can it be erotic for this kid ? Is he expressing fear, anxiety, insecurity, possessiveness ? Is it due to me living with my sister and her family ?
I'm totally lost, please help.

[Kevin Kennedy, Ph.D.]

Dear Michelle,

I can't speculate on the meaning of the behavior - your nephew would need to be evaluated to determine that. However, you all need to be more firm in your management of the interaction between you and your nephew. He should not be observing you when you bathe, and he should refrain from touching you in any way that you and/or his parents have told him not to. It sounds like you're not being authoritative enough with him - i.e., you and his parents are giving him directions, but you're not following through on those directions and taking charge of the situation. Remember, you're the adults - he's only four. You're not being insensitive by guiding him about appropriate vs. inappropriate kinds of touching or other behavior.

[halga6]

It's his way of showing his love for you. And I bet your feet are real special. Since he has had the privilege to smell them and feel them on his face he will do any thing to be your slave