Less than 1% of dudes can do this. And not like Clerks is a documentary but do be careful. Safety first, even (especially?) during autofellatio. That said, it is my understanding that yoga can be helpful for this undertaking, especially the plow pose. That's getting gravity to do some of the work for you. Although if you think about it, if you just save up the $15 or so you pay per class for yoga, you could afford a nice blowjob every now and again, and save yourself the trouble.
I've been dating this girl a little while, and when we had one of those kind of speculative talks about relationships and our dating pasts, she said that she would be cool with being in exclusive relationships for sex, but that she would always want to have multiple non-sexual BDSM partners. I was pretty thrown. I mean, we've done some kinky stuff but I didn't realize she was that into it. I guess I'm confused. Is that a thing? I thought the point of BDSM stuff was sex?
Sometimes it is, sometimes it ain't. Certainly lots of people engage in kink play in a nonsexual way, or in ways that some people don't experience as sexual and some people do. There is a whole giant wide range of fetish/BDSM scenes and interests and activities: flogging, domination/submission play, piercing, rope bondage, etc etc etc.
So yes, doing kinky scenes with people without having sex with them is totally a thing. I mean, legal dominatrixes don't have sex with their clients, obviously, in places where having sex for money is illegal, right? I am not an expert so kinky folks, please correct me if I'm wrong, but I think that many if not most scenes that people do at play parties or wherever don't involve having actual vaginal, anal, or oral sex. Whether the people involved in the experience feel that it is sexual even if it doesn't involve "having sex" in a more traditional sense is an individual thing. People are into kink/fetish/BDSM for all different sorts of reasons. Every person has their own boundaries, their own likes and dislikes, and their own goals and desires.
However, I do think that, depending on what she's into, it can be a very emotionally intense experience to have with someone. Again, it varies from person to person, but I would think that someone with the expectation of a super-traditional monogamous relationship might be uncomfortable with having a partner play, even nonsexually, with others.
Which, of course, isn't to say that those are your expectations. I don't know how vanilla you are, or whether monogamy is even your thing. I do think if the two of you are talking about getting more serious in your relationship, this is probably something you need to have some more conversations about. You'll both need to decide what your boundaries are and what you require in terms of extra-relationship play, and whether you can find a set of relationship rules that you're both happy with. Definitely have these conversations before you make any kind of commitment, because not being clear with each other about your expectations is a really great way to have hurt feelings.