fained > was eager; or: feigned mistake > mis-take, fumble
3 And in her lap did shed her idle draught,
idle > unavailing
4 Showing desire her inward flame to slake. 5 By such close signs they secret way did make
close > secret
6 To their wills, and one eye's watch escape: 7 Two eyes him needs, to watch and wake,
him needs > [are necessary to him] wake > remain awake, keep guard
8 Who lovers will deceive. Thus was the ape,
ape > fool ("to put an ape in his hood" is to make a fool of some- one: see Chaucer, introduction to The Prioress's Tale, 1630)
9 By their fair handling, put into Malbecco's cape.