It has been my fantasty for a long time to have DP, I have seen lots of porns with TP and even more than Triple! I was astonished to see that it could even be done! The main reason I've not attempted DP yet is because I'm a large woman and I'm worried about the whole 'gymnastic' part of doing DP, and would feel pretty embarrassed if because of my size we couldn't get in the right positions for it.
I certainly wouldn't attempt TP unless I'd had some DP sessions first to get used to it and then I'm guessing I'd need to work on stretching out down there a bit too before attempting to get more than one in the same hole! Also with that being said, at this stage I wouldn't even consider three in the same hole, but with that practice and stretching before hand, could consider 2 in one hole and 1 in the other! Maybe a fourth in my mouth? I've found that if I'm stretched out with that pleasure AND pain feeling, having my mouth filled at the same time helps me stay with it and not focus too much on the pain part and so making it easier to really get in to it and enjoy it more.