The "politics" in question are about Rin having the hots for Yuu, he wouldn't have bitten her if he didn't, and the implications of the sexual pleasure when bitten.
Nowhere in the manga does it say that the urge/need/desire to bite someone is linked to attraction tho, neither is it implied anywhere.
it only says that pleasure if FELT when DOING the biting.
ppl just over-thinking this and cluelessly spit-balling.
Ch. 3 Page 8:
"The fact you only want to suck blood from women means that's your preference" (bold in the original)
Ch. 3 Page 10:
"So vampires suck blood from people they find attractive?" "Yeah, more or less"
"So, given that you sucked my blood, does that mean I'm your type?" (flustered reaction)
Neither said nor implied? Really? Looks like it's right there in black and white to me.