having troubles with my mom?

well it all started when my mom found out that my sis was talking to some guy online when my sis ran away to go and meet him. My mom hated the guy but eventually she was curious who he was and it just "happened" that my sis wanted to go to a college that is 10 min away from his house. well one day we actually met him and my mom turned out to like him and everyone in the family is all cool with him talking to us and stuff. Well my mom pays way to much attention to him and not even me, her own son. She goes out and buys him things and when we are with him i always get yelled at for talking, my mom says that i just make him feel uncomfortable and i dont see how i do, im not rude or anything.

When she went to Florida to see her brother she came back with some gifts, she gave me a t- shirt and a old star fish and kinda just gave em to me casually. Then she told me to go out in the car cause she has more stuff to Florida to bring in and i got kinda excited cause i thought it was for me but it wasn't, i found out that she had bought the online things, so much for a matter of a fact she bought a medium sized suit case to fit it in. i got really mad and my mom doesn't think she is doing anything wrong.

I am really mad that my mom is caring for him more than me, when she gets home er and my sister are always talking about what they should get him and stuff and she is spending all this money. I asked her for a pack of gum cause she was going out shopping and when she came home she had bought him all these things and i asked did u get my gum and she said "no i dont have the money for that.

What should i do? its really annoying and i hate it how she treats him way better than me.