We are not ruled by DUP MPs, they represent the majority in Northern Ireland. They have every right to put the interest of their constituents first. They also respect the referendum result which you seem unable to.
They certainly do not represent the majority in Northern Ireland. 500,000 voted for other parties as opposed to less than 300,000 for the DUP. The Tory party blew the last election, and cannot govern without buying the DUP vote, and we can see how without their support your Brexit is a failed project.