Yep. Several times, but it's been awhile.
One time my neighbor (female) and I were texting about a project I was going to help her with, and I was jerking off the whole time (but I didn't tell her, of course, since it was unrelated). Near the end of the text, she texted, "well, I didn't think I would ever make myself cum while texting about building a fence!" I didn't respond that we had, essentially, cum together while texting about a fence; it was merely coincidence. (We have text conversations like this all the time. It's super weird, I know. We are not attracted to each other at all, none, which is probably why it's easy to have these ridiculous conversations.)
My wife has cum several times while on the phone with friends and even her parents while we have sex. She usually mutes the phone while they ramble, but one time she didn't mute the phone and her friend got pretty quiet once she realized what was going on!