Does this happen to anyone else? It's starting to hurt my feelings...?

I am a SAHM to a wonderful 21 month old. He is my whole heart. Well my MIL watches him twice a week while i go to Dental Hygiene school. Whenever i go pick him up he gives me a slight smile, and then suddenly remembers that im there to take him home so he runs away yelling no no no! He acts like he is not happy to see me at all. It is family knowledge that she lets him get away with murder over there, he pretty much has no rules when he is with MiMi. Pretty much anytime she is around he turns into this whole different child, he is more whiny, he doesn't want anyone but her...and of course she eats it up. If he gets in trouble by my husband she will pick him up and say "its ok, its ok poor thing" Im glad that my son is able to have a good relationship with his mimi, everyone should have a good grandma. I even care about her a lot. and im not ever mean to my son, i don't get on to him for stupid things, and when it is just me and him we have the best time together. He is so loving and kissy towards me when she isnt around. It's all about mommy. I just don't understand why he acts like I am spawn of satan when i come to take him home at the end of the day. I don't mean to sound whiny, It is just starting to hurt my feelings! I mean come on! no one loves him more than his mommy does! Does this happen to any of you? why? and how do you deal with it?
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I think this is pretty normal. My husband, daughter (15 months) and I are temporarily living with my parents. When it is just myself and my daughter things are great but when my mom is home my daughter simply ignores me and her grandma is her favourite person! I understand how you feel but like you say you can be comforted in the sense that he loves his mimi. It is very normal for kids to love their granparents in a special way like that, it doesn't mean he loves her more, it's just something different. I also remember when I was young and my mom used to sit our neighbours children in the day. When their mother used to come and pick them up the children used to act the same way you have described, it seems to be a normal behaviour.
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