My W does not like a lot of manual or oral stimulation. She said to me that it feels great, but it gets her only so far and then plateaus (there are exceptions to this rule, however)...she needs to feel me inside her to reach her "O".
The truth was that I felt that there was no chance of getting to O, so at some point I preferred simply to get the foreplay over with, along with the IC and fake an O.
I was content not to O because I had no expectation of ever being able to reliably O with a P. That expectation changed when I came clean with new H, was more authentic and vulnerable in SL and didn't have a big secret and became more honest about my needs. I then began to O reliably and I became far less content with the sex-for-closeness-not-O thing, and probably experienced real frustration at not Oing during sex for the first time because I wanted to and understood it to be possible.