BEROWNE But there are other strict observances: As not to see a woman in that term, Which I hope well is not enrollèd there; (1.1.37-39)
Berowne would love to study for three years, but not if it means he doesn't get the pleasure of female company. He doubts any of the lords can stick to this plan, but eventually agrees anyway.
COSTARD Such is the sinplicity of man to hearken after the flesh. (1.1.222-223)
For Costard, this goes without saying. It's a truth that the lords will have to learn.
BOYET Why, all his behaviors did make their retire To the court of his eye, peeping thorough desire. (2.1.246-247)
Boyet describes the King's eying of the Princess. Have you noticed that, in this play, attraction is all about the eyes?
ARMADO My love is most immaculate white and red. BOY Most maculate thoughts, master, are masked under such colors. (1.2.90-92)
Armado is describing Jaquenetta's beauty, but Moth takes the opportunity to make a bawdy joke about the colors involved in sexual arousal.
MOTH 'The hobby-horse is forgot.' ARMADO Call'st thou my love 'hobby-horse'? (3.2.30-31)
Armado is right to get offended. In Elizabethan slang, a hobby-horse was a prostitute.
BEROWNE Ay, and by heaven, one that will do the deed Though Argus were her eunuch and her guard. (3.1.208-209)
Berowne fantasizes about having sex with Rosaline even in the face of scary obstacles.
MARIA You still wrangle with her, Boyet, and she strikes at the brow. BOYET But she herself is hit lower. Have I hit her now? (4.1.136-138)
Rosaline may have won this round of wit with Boyet – but she can't win against her sexual desire. This mind/body divide is a big theme in the play.
NATHANIEL Sir, I praise the Lord for you, and so may my parishioners, for their sons are well tutored by you, and their daughters profit very greatly under you. [...] HOLOFERNES …if their daughters be ingenious, they shall want no instruction; (4.2.90-93; 95-96)
Yes, Holofernes seems to also have his mind in the gutter. The love fever affects almost every character in the play, even the learnèd and scholarly teacher.
BEROWNE This is the liver vein, which makes flesh a deity... (4.3.74)
Berowne overhears Longaville fantasizing about paradise with Katharine. In Elizabethan science, the liver was considered the source of sexual desire.