Why do we get some explicit references in Shakespearean plays that are meant for something else?

Question

First of all, by “explicit contents” I really mean the that thing.

In Shakespeare's play Julius Caesar when Brutus had planned everything and the night before the assassination he was in his room he had a little conversation with his wife Portia. During the conversation Portia says

Giving myself a voluntary wound
Here, in the thigh: can I bear that with patience.

Why we got such an explicit reference in between such a serious and intellectual scene? Why writers put those things in plays which shouldn’t contain it (in my opinion).

I got one more example (suggested by @Rand al’Thor) from Romeo and Juliet, Act II, Scene IV we find

"the bawdy hand of the [clock] dial is now upon the prick of noon".

Please understand that I’m not criticising any playwright all I want is to know why it’s important to make such references when things are better without them (in my opinion).

DEFENCE: Users are asking me to clear out what I think about “thighs”, well (@MattThrower has pointed out) it is “thigh” which is used in that verse not the “thighs”. I think the word “thigh” refer to something explicit or as something pre to reproduction act because a women don’t talk about their body parts which are close to genitals (as far as I have been around with relatives or acquaintances) and “thigh” is quite close (near) to it. The problem is why would a woman inflict a wound on her “thigh” rather than on any other place, what’s the significance of “thigh” in that verse.

Answer 1

The discussion of sexual allusions or inferences in Shakespeare has been going on for a century or more. There can be no discussion, though, about the second quotation. (the bawdy hand of the dial is now upon the prick of noon). It's dirty. To answer Knight's question: Shakespeare's trade was theater, not literature. He wrote with his audience in mind, not literary critics and scholars. The word "prick" appears six times in Act II, Scene 4 - and nowhere else in Romeo and Juliet. It is there to entertain his audience, who would have started chuckling at the fourth or fifth "prick." Maybe it's a stretch, but one might also say he was training his audience, training them to listen, training them for Hamlet, Lear, The Tempest.

Answer 2

The most famous study of Shakespeare's "explicit references" is Shakespeare's Bawdy: A Literary & Psychological Essay and A Comprehensive Glossary by Eric Partridge (first published in 1947). The book contains a 48-page introduction, followed by a 175-page glossary.

I hope it is clear that what is considered taboo or inappropriate varies through time and from culture to culture. On page 33, Partridge writes,

On the other hand, there is much evidence to show that in late-Elizabethan, in Jacobean, and in Caroline times, women spoke very freely of sex in the presence of men and that the men and women of those times conversed together, with considerable freedom, on the theme of fornication and 'wedding and bedding'. The comedies of Ben Jonson, the comedies and tragi-comedies of Beaumont & Fletcher, Heywood, Massinger, Middleton, offer many proofs of this freedom. Shakespeare and Beaumont & Fletcher were quite as 'free' as were Dryden, Etherege, Wycherley, Congreve.

In the fifth and last part of the introduction, Partridge asks how Shakespeare compared with other Elizabethan and Jacobean dramatists in the matter of sex and bawdiness, and writes,

Of all the dramatists flourishing in the Elizabethan and Jacobean periods, Shakespeare is the wittiest, profoundest, most idealistic yet most cynical, and, proportionally to the corpora operum, the most abundant: Lyly, Marlowe, Kyd, Greene—Ben Jonson, Webster, Tourneur, Heywood, Dekker, Massinger, Middleton, Beaumont & Fletcher: all these men are inferior, in all those respects, to Shakespeare, and only Jonson in his comedies and Beaumont & Fletcher, whether in comedy or in tragi-comedy, are as smutty; but unfortunately the smut of Ben Jonson, as of the collaborators, is less witty, (...)

Partridge also claims that Shakespeare's interest in women and their sexual features "was part of his character and his temperament" (page 21) and that he did not want to hide this. He does not believe that Shakespeare's bawdy jokes were concessions to the groundlings (page 3).