the art of compromising

is compromising an art of any way?
is compromising really a must in a relationship?
well i say yes!
we say yes!
hell of a lot of people say hell yea!
now listen to my story yall:-
i'm in a relationship with some one, that i love deeply, yes i get hurt alot from some of the senseless jokes i get - though he doesnt meen them -, i do alot of hurting too, concedring my age, and my hormones, my act will be pulled up together at the age of 21, or 20, somewhere in between, we are close, in love, happy most of the time, but these few days we are getting a rough edge, you see, i wasnt a sexualy active person, a kiss was the farrest thing i concedred reaching, but after a really hard slap in the face, and mis-judgement, not to mention heartbreak, i agreed about being sexualy active, hated the thought of it yes, but then i got sucked into it.
now after that, the person i'm in a relationship with wants me to do something more, something i've experience in my early childhood and didnt really like it, this thing is addictive, and i've tried hard, well hard is a very light word concedoring what i've tried :s, not to get addicted to it.
my other half told me more than once, after me passing 21, i'd be exposed to that matter, now he is demanding that i be exposed now, saying that he had experinced it befor, though in more than one conversation, he said he never did it.
so do i compromise?
i know u guys will email me asking what the heck am i talking about, just like some other posts, this subject is deep, and i only know one thing, i feel like a cheap easter bunny, i look good, but i'm tastless, and hollow from the inside...
one other question, why do we compromise?