Don't cop out of doing your share of the work.
cop out
idiomTo avoid or shirk, either by failing to perform, or by performing in a grossly insufficient, negligent, or superficial manner.
Origin
first recorded 20th c.Attested since 1942 as “flee, escape, cop (an) out”.
He decided to cop out of the difficult project by claiming he was too busy to help.
Rather than addressing the fundamental flaws in his proposal, he chose to cop out by offering a series of vague and unhelpful excuses.