Q I'm a young heteroflexible guy who's been a "sugar baby" for a handful of wealthy older guys. I love it! I get money, I have fun being with them, and the guys seem to like having me around. The problem is that I just got with a new guy who's really great except for one thing: he's HIV positive. He says that his doctors predict he won't have a shortened life span and may not even have any symptoms that would make his life uncomfortable. I like the fact that he told me, and I'm open to being with him sexually even though I'm HIV negative and want to stay that way.

He's very submissive—he wants to be used and abused sexually, physically, and mentally. My question is, what kinds of sex acts are OK to do with this guy? I read on one site that him rimming me is fine, and on another that him giving me a blow job with a condom is safe too. But I can't find a site that specifically explains which sex acts are safe and which ones aren't when one person is positive and one person is negative. —Help in Virginia

A It's pretty simple, HIV: Sex acts that expose you to his semen and/or blood are definitely unsafe, and sex acts that expose him to your semen and/or blood are mostly safe. Rimming you, blowing you (even without a condom), getting fucked by you (with a condom)—all very low risk for HIV transmission. If he's on a drug regimen and his viral load is undetectable, HIV, your already-low risks of being exposed while, say, accepting a blow job (and a check) are even lower. The risks aren't nonexistent—all sex acts carry some degree of risk—but if the risks were any closer to nonexistent, they'd be sitting on nonexistent's lap.

And bear this in mind: odds are good that some of the other guys you've babied for—some of your previous daddies—were HIV positive and either didn't know or didn't have the decency to tell you. This guy's willingness to disclose is evidence not just of his honesty and decency, HIV, but of his respect for you and his commitment to keeping you safe. This guy is less likely to ask you to engage in sex acts that are higher risk or unsafe than a guy who isn't aware that he's positive or is actively hiding the fact that he's positive. And his interest in being "used and abused" creates lots of hot safe-sex-play options—letting him beat off while he licks your boots or jerking him off while he's tied to the bed with your jock in his mouth are no-risk sexual activities that he's likely to enjoy immensely.

Q I'm a 24-year-old straight guy. I've been with my girl for three years, and things are great—great sex life, great communication, etc. We have lots of sex, but for the last year or so she hasn't been on birth control and we haven't been using condoms. We're not against the idea of a child, but we aren't currently going for it. I was always told that pulling out was a 100 percent ineffective method of birth control. So my question is, I guess, could there be something wrong with one of us? How could we have unprotected sex for a year without getting her pregnant? We both really want children eventually and are worried it might not happen. —Sent From My iPhone

A Withdrawal is a much more effective birth control method than most sex advisers are comfortable acknowledging. But facts are facts: a comprehensive study conducted by researchers at the Guttmacher Institute found that withdrawal was almost as effective a birth control option as condoms. According to "Better Than Nothing or Savvy Risk-Reduction Practice? The Importance of Withdrawal," in the June 2009 issue of Contraception: "If the male partner withdraws before ejaculation every time a couple has vaginal intercourse, about 4% of couples will become pregnant over the course of a year." That compares pretty favorably with the 2 percent of straight couples who'll become pregnant using condoms perfectly over the course of a year.

In the real world, of course, very few people do anything perfectly. When you take mistakes, leaks, and broken condoms into account, researchers estimate that 17 percent of straight couples who rely on condoms will become pregnant in any given year. Not all withdrawers use withdrawal perfectly, either—amazingly enough, some guys get distracted and forget to pull out as their orgasms approach—but the research shows that just 18 percent of straight couples who use withdrawal will get pregnant in any given year.

So odds are good that you're not infertile, SFMi, just lucky.

Q I'm a young lesbian. I recently met a girl who's cute, and I think we're on the likely-to-have-sex-soon track. The thing is, she confided in me that she's participated in needle play in dungeon-party situations. I'm not someone who's turned off by kinkiness just 'cause it's kinky, but it seems like even "safe" needle play is a recipe for STI transmission unless you're playing with trained medical professionals. She says she gets tested regularly, but still, would it be really risky for me to sleep with her? —Enthusiastic Reader

A Every time I've watched needle play in a dungeon-party situation—watched with my hands clamped over my eyes, peeking through the small spaces between my fingers—no one was being stuck with rusty needles by dirty-handed brutes. All the public needle-play scenes I've witnessed were ostentatiously sterile affairs: these kinksters, some of whom were trained medical professionals, made a big show of using alcohol wipes, cotton swabs, latex gloves, and clean sharps. I think it's fair to ask this girl for more information about her blood and needle experiences, about the safety precautions that her partners took, and about how recently she was tested. But rest assured, ER, that the most effective STI transmission routes involve sticking dicks in people in completely vanilla situations, not clean needles in dungeon-party situations.

Q Here's some information for MILK, the man who's aroused by the thought of being sprayed with his wife's breast milk: it's common for newly lactating women to experience strong "milk-ejection reflexes" during sex. This is induced by the hormone oxytocin, which is released during labor and orgasm, and when the milk "lets down" during breast-feeding. In other words: new mothers often spray milk when they get off. Most women are embarrassed when this happens, but at least MILK's wife will know the first time it happens that her husband isn't going to freak out about it. —Breast-feeding Educator's Sex Tips

A Thanks for sharing, BEST.

Confidential to American ladies: Republicans took the House of Representatives after campaigning on jobs, debt, and taxes. But it's been nonstop assaults on Planned Parenthood and reproductive freedom ever since. The GOP is always going on and on about how they want to shrink the size of government, and now we know why: they want to stuff the government in your vagina.

Confidential to Canadian everybodies: Please go to shitharperdid.com, have a laugh, and then do what you can to send Stephen Harper packing or, failing that, deny him a majority. Pretty please?

Send letters to mail@ savagelove.net. Download the Savage Lovecast every Tuesday at thestranger.com/savage.