I've been slowly working on getting a prostate orgasm over the last year or so. It's been slow progress because I don't have a lot of opportunities to play with myself and give it the time and slow work it needs, but I've gotten pretty close. I have a dildo that's about 10x6.25 and a couple of times when I've been really open and really going at it with the toy deeply inside me I've gotten to the point where I felt something building and I've even spontaneously squirted out some pre-cum, but I've never gotten the feelings to roll over into the release. But it feels so great that I don't mind having to jerk off to finish after the fact, and I'm looking forward to trying more and eventually getting it.