My laptop keeps connecting to the internet through another computer

Hi,

I have had my xps m1330 laptopfor 3 years now.

I have moved into a new flat with my cousin and have BT as our internet providers. The wireless router was just put in last month.

We both realised that when we are both connected to the internet, it is really slow. I then noticed that we both shared the same IP address which is weird.

I then looked on the network and sharing center which stated that my laptop was connected to multiple networks. I clicked on view full map and it showed that:

MY LAPTOP-------WIRELESS ROUTER------COUSINS LAPTOP------NET

Im assuming this is the reason why we both have the same IP address and the net has become really slow when we are both connected. This is because of us sharing the bandwith. nb. there is no problem when only one of us are connected to the internet.

Therefore can someone help me to find how i can connect my laptop to the internet without going through my cousins computer? I have both tried disconnecting from the network and then me connecting again. Then there is no problem. But when he connects tot he internet, my laptop wants to connect through his laptop to the internet. On my cousins laptop it just shows:

HIS LAPTOP------ROUTER-------NET

Therefore it must be something to do with my laptop. is there a setting or something i can do to my laptop?

Please help, would be much appreciated.