I care for my girlfriend, whom I have been seeing for a few months now. I have no problem maintaining an erection when she performs oral sex on me. In fact I can climax twice in a relatively short time. We have, however, been unable to actually engage in intercourse, since when we go to put on the condom, I lose my erection. I'm not really having too much of a problem getting erect (i.e., I get an erection, and may lose it early on, but I am able to get and maintain another one for oral sex). What could be the problem? Stress? A lack of physical attraction? I will be grateful for any answer you can provide me.

I noticed that you have information on tubal ligation (surgical sterilization for women), but not on Essure. Can you tell me more about it? What are the risks and benefits?

If my husband takes antivirals or post-exposure prophylaxis can we still have sex with a condom and still complete the process like normal? It is affecting our sex life because he does not want to infect me. I don't want to be infected but I knew what I was getting into from the start. I might start PrEP as it is now available to me. What are your thoughts?

I've been taking birth control pills for almost seven years and decided to stop taking them as of my last cycle last week. What kind of changes should I be expecting? How long will it take for my body to get used to not having the hormones? In the past few days, I've been feeling very edgy, tired, and with on and off headaches. Is it true that once you withdraw from birth control pills, you may actually lose a few pounds?

Quite often when my boyfriend and I have sex, the condom disappears into my vagina. As you can imagine, it is extremely mood killing and a little disconcerting for me to have to reach up there and find it. I read your response to another couple with the same problem, and we'll definitely make sure to hold onto the condom before pulling out. I use Depo-Provera (so the condom is used just to be extra sure), so I'm not particularly worried about pregnancy. What I would like to know, though, is why this happens to us so often? I've never lost condoms with any other partners. I also have the feeling sometimes that it might be coming off before ejaculation. This seems to happen quite frequently (one out of every two or three times we have sex). It's kind of frustrating. Is there anything else we could do differently?

I have heard that it is unsafe to keep condoms in wallets, since they can get broken or weak with all the bending the wallet does when you sit down. Is that true?