My wife and I have had some MMF threesomes and on a few occasions she has been DPed and enjoyed it very much.
The first time was with a very close friend so I was comfortable with the situation. That was many years ago and I would now gladly share her with whomever she chose.

If you want to give your girl the sensation of being DPed, try suggesting she use dildo on herself while you fill her ass.
Caution: this may just wet her appetite for the real thing!

Have fun!!