Are we compelled to sin by original sin?

No. Man, though, is deeply wounded by original sin and is inclined to sin. Nevertheless, with God's help he is capable of doing good.

In no single case are we obliged to sin. In fact, however, we sin again and again, because we are weak, ignorant, and easily misled. A sin committed under compulsion, moreover, would be no sin, because sin always involves a free decision. (YOUCAT question 69)