Definitely real!
I'm a 100% bottom and I tend to cum handsfree pretty much every time, but I think it really depends on you as a person. Personally, I find being on top facing him provides the best results, no matter dick size, girth, whatever. 7 inch dicks and 3 inch dicks have done it both for me ! I also personally dont like doggy at all really because it's more uncomfortable than pleasurable, but that's just me.
I think you also have to build up before hand. I think there were a few times where there was little foreplay before hand ive managed to do it, but I think if you edge really strongly with oral, rimming, kissing, jerking and stuff, then move onto sex and find your position, that'll probably be the best bet!
Id say its also a bit of a mental thing. There have been 1 or 2 instances where ive cum handsfree after little foreplay beforehand and it really felt like I almost thought myself into cumming! Like obviously it felt good but I remember reading an article about how women could purely think themselves into orgasm (think Friends and Monica explaining the 7 erogenous zones), and I really felt like I helped that anal orgasm from thinking about it hard enough.
Also I have to admit its so much better than cumming from just oral or masturbation alone so Ill cross my fingers for you!

if you want the ultimate experience , if you feel the handsfree orgasm coming (haha pun intended), after you start orgasming start wanking yourself off for the best cum of your life. I tend not too really because I always like to surprise and excite the guy im sleeping with showing him i can cum handsfree.
Hope this helps a bit!! let me know if you want to know more