I have done it in the past & to my great surprise i really enjoyed the experience. It was something different & i’ve always enjoyed trying different things before passing judgement. Surprisingly i even preferred that experience over the usual threesomes (with 2 females) that i’ve had. If your a sexually active & open-minded person it’s definitely something i’d recommend giving a try.
I think the exciting part is seeing the facial expression of the girl while she blows 2 dicks and also when she gags while she’s getting penetrated. It was good to try to say I did. Whereas for a duo with 2 girls if the girls are not bi or if they are shy it could get boring and better to see them separately. My 2 cents