OP, please check out my recent thread in basic drug discussion titled "Demerol - The perfect sex drug?".
Your thread is very interesting for me because as a male I have always wondered how opioids affect the sexual performance/experience of females as opposed to males. None of the girls I have ever slept with were opioids users, so I never had the opportunity to share my oxy with my sex partner. I always imagine however that it would make the girl less horny, considering that she would be feeling really good already and care about sex less. (Thats how I sometimes feel, I'm just taking the opioids in order to please my girl more, although I don't feel that horny myself!)
I have been using opioids sporadically for the last 7 years since the age of 16, my typical dose is 5-15 mg of Oxycodone. One of the first "Side-effects" I noticed was that I could fuck for hours, though if I used too much I might not be able to keep hard...and it also decreased my libido somewhat.
However, I have found that it does not require a "recreational" dosage to increase sexual performance. By that I mean that I can take half the dose of what it takes to get me high and still have increased sexual stamina. So for me, I normally take 10 mg oxycodone to feel nice...but if I plan to have sex I take 5 mg oxycodone about 20 minutes prior to having sex. It has worked well for me in the past aside from a few times where I took too much oxy and wasn't really interested in the sex (since I was feeling so good already!).
DEMEROL - I just tried this drug for the first time last weekend and I found it to be superior to oxycodone in improving my sexual performance/experience. I only took 100 Mg on an empty stomach late Saturday morning....I never really felt high that day (comparable to 60 mg codeine), and 9 hours later I was practically sober before having the best sex with my gf ever. We had sex for over an hour and I was able to keep hard and maintain control over when to ejaculate. She was really horny too, even though she doesn't take any drugs...I think she was loving the fact that I was so focused on the sex. Normally opioids dull my sexual drive, but the "after-glow" of Demerol seems to have many positive aspects.
I suggest you all check out my thread, and if you have any experiences with Demerol and sex or low-dose opioids and sex please share!