Have him read this and get back to you :)
A shocking number of husbands do not understand just how much they are asking for when they demand MIL be allowed in the delivery room. DH and I have discussed posts here and he once commented that men just don't have anything to compare it to. Guys haven't grown up hearing stories about delivery stalling out or what exactly constitutes a 4th degree tear. (Not an excuse!) Anyway, I don't claim to be a guru but maybe the following could help somebody get through to a misguided but otherwise decent DH.
Here's a little visualization technique I like to call Scrotum Squats.
You agreed 9 (10!) months ago to a round of Scrotum Squats. At some time in the next couple of weeks, you will pee yourself or receive some other signal that it is Squats time. You rush to the hospital where a nurse clamps a weight to your scrotum. Every 5 minutes you must do squats for 15 seconds. You can sit in between. (Good luck getting comfortable!) Over time you will have less resting time and longer squatting time. There will be absolutely NO removal of the weight at any time...even if you have to pee. Oh, did I mention you have to do this in a gaping hospital gown? A nurse will come inspect your swelling nuts every once in awhile. (Pray for the gentle one!) After 10 hours, the event will culminate in somebody yanking the clamp off without loosing it. Don't worry, if you tear they will stitch you up!
You may invite your FIL to help/witness your Squats. Any time his eyes stray to your tormented balls or he irritates you in any way, your Squats timer has a 1 in 5 chance of increasing by an additional 30 minutes. Please keep in mind that you will be exhausted and in a great deal of discomfort so your irritability will be even higher than usual.
You agreed to play Scrotum Squats in order to have a lovely little baby with your wonderful wife.
Do you really think it would be fair for her to whine about wanting her Daddy there while you are busy Squatting your balls off?