Internet DC from server Question

so i have this problem everytime my IDIOT dad goes on the internet from his laptop from direct cable from router he disconnects me from CF its gone to the point where i want to murder small children!!!! all the kills exp gp ive lost over the years WHEN I THINK OF IT I GO INSANE!!!!!!!! AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH

anyways is there a way to make it so he wont do that .... i have a direct cable into the router same as him to my computer in my room .... the router is connected to the modem ..... we have comcast isp ... so what can i do so he wont disrupt my connection from crossfire when im in game when he plugs in his direct internet cable to his laptop . or do i have to get a router all to myself ... or what!!!!