Instruct: Classify Amazon reviews into positive or negative sentiment
Query: irritating for the girlfriend

felt pretty good on my end, but my gf had an allergic reaction to the nonoxynol-9. if i understand correctly it's not used very often in condoms in the states because there is no evidence that condoms lubricated with N-9 are more effective in preventing pregnancy than condoms lubricated otherwise. wouldnt buy them again