Well I guesss you should want him to invite you into games more often then.
I got Call Of Duty 4 on DS today. I've only done the first mission in campaign mode and it seems quite decent. I wanted to get it mainly for multiplayer purposes. I'm hoping my brother gets a DS. Otherwise, I'll have to invite the 8 year old girl who lives around the corner to come over for some Call Of Duty 4 action~!