I’m sure I’ve slept with married people before, but until relatively recently, I’d never had an affair or a sustained relationship with someone married, and both of those situations have given me a lot to think about.

In the case of the affair, it started off with a bit of flirting, mostly by email, phone and text. In the beginning, I assumed that because the man I was seeing was in an open relationship, that his wife knew, and once I found out she didn’t, I was so heavily invested in what I wanted from him that it didn’t matter. My general opinion is that it’s the partner’s responsibility to deal with intermarital communication, not an outside party’s job to police someone else’s marriage, if that were even possible.

At first, it was hot, and even made me feel special to be having this secret affair. Any time he could have been with her and chose me, I felt like I’d done something right, but it wound up having the converse effect, too, because invariably there were times when I thought we’d get to spend together that we didn’t. I found this unearthed cache of jealousy buried inside me I never would have guessed at, and thanks to social networking and Googling, I stoked that jealousy until it became highly problematic.

I decided when that relationship died down, with a lot of sadness on my part, that I didn’t want to partake in secret rendezvous in the future. I didn’t feel guilty because I didn’t believe she’d truly mind if she knew, but it made it even more awkward to have to pretend I didn’t care about him if I ever saw them together in public. Plus, I couldn’t go to dinner and hold hands with him, or take him to hang out with my friends.

I’ve recently started seeing a woman in pretty much the opposite situation. She’s married, but her husband knows exactly what’s going on. I was at her place once when he called and she said, quite casually, “Rachel’s here.” I liked that it wasn’t a big deal; that he knew who I was and didn’t mind.

My friends have met her, and even though there have been a few awkward questions (“So you’re married…and your husband knows about this?” a new acquaintance asked as we held hands), for the most part, it’s no big deal. As long as I’m cool with it, they don’t care that she’s married. I like that we can go out in public and there isn’t any inherent drama. I found the secrecy of the other relationship stressful, and it impinged on the time we could spend together, which was already very minimal.

I don’t think it’s easy, though, to date someone already 10 or more years into a lifelong relationship, especially if that is the kind of partnership you’re looking for. I have no marital aspirations myself, but I do want to settle down and have kids, or have them on my own, and I don’t have too much time left to do that. In a lot of ways being with someone married only serves to highlight what I don’t have in my life, even though I’m not sure I’d want to be married if given the chance.

There’s no denying that even if you aren’t directly dealing with your lover’s partner, you are still sharing a very important person with them, thereby entwining your lives together. Whether that person knows about you or not, they are there, and a constant presence, even if their name is never mentioned.

As the extra person, you are never going to appear on the “in a relationship with” section on Facebook, or get mentioned alongside them in any public forum the way a spouse does. No matter how much I discover about their relationship, I will never be in it, and I do tend to think that automatically creates a distance that isn’t there when you’re in a monogamous relationship. I’m not saying I don’t believe in polyamory, but that being in a secondary relationship, for me, isn’t as all encompassing as a primary one, and I don’t think it should be.

Dating or sleeping with these married people has given me insight into marriage that I don’t get even from my married friends, because even the most oversharing types don’t share the kinds of telling details lovers do. Because you’re negotiating schedules, you learn whether they’re pretty much inseparable or spend significant time apart. In the case of the married guy I was seeing, despite my probing online, I didn’t ever want to hear about his marriage, and avoiding the topic was easy, for the most part.

With the woman I’m seeing, because everything is more upfront, and because we can actually spend time together in public and private, without jumping through hoops, I do get more detail, and it helps me get a better sense of what her life is like.

For me, in both cases, it’s been a way to observe from afar ways of enacting long-term relationships, and has helped me figure out what I would and wouldn’t want from one. I’m pretty sure I couldn’t handle being in a long-term relationship and having another relationship on top of it, but I admire those who can seamlessly juggle the two.

I think gender plays a role, in my case, because I fell into an extremely stereotypical jealousy in the first relationship. Especially as that relationship died down and I lost what had felt like a major connection with him, I found myself lamenting all the ways I didn’t measure up to his wife, all the ways she was better than me. Clearly, that is not healthy behavior, and I take full responsibility for it, but I also know that I let my heart get too involved with someone who was clearly not as available as I’d have liked. I don’t regret that, because seeing the depths of my own jealousy has helped me navigate other relationships and potential ones.

I don’t identify as monogamous or polyamorous per se, though I suspect my inclinations are more toward the former than the latter, but I’m glad that both these examples of open relationships have taught me not to make generalizations about “marriage” or about my own needs and desires. Ultimately, everyone is different and I’m the kind of person who learns by doing. I haven’t had to explain this setup yet to new dates, and I don’t know quite what will happen when I do, but that is all part of the learning process.