In my case, the combination of the two brought about an underlying anxiety disorder. Mixing drugs can do a lot of harm, especially since everyone is different and dosage can vary between person to person. I highly recommend against this due to it taking me a few months for my "brain to reset" and feel normal ( I actually made a post back in January of what happened to me when I combined the two).
But as I said also, everyone is different. Most likely you will try it anyway. The way I did it, was I took the shrooms right as I was coming off the peak of rolling (sort of to use MDMA as a baseline) and within 45 minutes or so the effects became very evident. I could still feel the MDMA (I took 200-215MG whatever was in the pill) then about 1.7G of cubensis shrooms. It was very enjoyable and almost life changing at the time! I still love thinking about how amazing it was, a very fun trip.
But the lasting effects of drug combos can be devastating. If you hardly ever roll and hardly ever do shrooms I would combine these for one special night and then lay off for a while. Again, NOT recommended because you can risk some serious damage, but if you do it sparingly in moderation...I think it will be "okay".
Be sure to take less MDMA and less than normal dose of shrooms. I took too much MDMA for me to hippyflip, it was overly intense (in a good way, but was overwhelming at some points)