Sonnet LXVII (67)

Ah! wherefore with infection should he live,
And with his presence grace impiety,
That sin by him advantage should achieve
And lace itself with his society?
Why should false painting imitate his cheek
And steal dead seeing of his living hue?
Why should poor beauty indirectly seek
Roses of shadow, since his rose is true?
Why should he live, now Nature bankrupt is,
Beggar'd of blood to blush through lively veins?
For she hath no exchequer now but his,
And, proud of many, lives upon his gains.
O, him she stores, to show what wealth she had
In days long since, before these last so bad.

3. That sin by him advantage, &c. His presence serving as a veil to conceal corruption. 

4. Lace itself with his society. "Lace" may here mean "embellish," though in passages which have been quoted in proof the sense is rather "diversify." So in Romeo and Juliet., Act iii. sc. 5, lines 7, 8, --

"What envious streaks
Do lace the severing clouds in yonder east;"

and Macbeth, Act ii. sc. 3, lines 117-119, --

"Here lay Duncan,
His silver skin laced with his golden blood;
And his gashed stabs looked like a breach in nature,"  

6. Dead seeing. "Seeing" is equivalent to "appearance." Cf. v. 2, "The lovely gaze where every eye doth dwell." The "seeing" is "dead" as not being the result of healthy vitality, but mere imitation. 

7. Poor beauty. Beauty indifferent and imperfect. Indirectly. By artificial means.

8. Shadow. Mere external appearance.

12. Proud of many. On account of their seeming beauty, which, however, is not caused by "blood blushing through lively veins."