Husband wont mow?

Is this normal? My husband will let the grass grow until its shaggy, and then keep saying he will “do it tomorrow” but doesn’t. I am 9 months pregnant, and tried to get it done while he was napping the other day, but got too hot and had to stop.

I don’t want to “nag” ...but it’s getting ridiculous. I mentioned it to him today and he got very angry, slammed a door and has been giving me the silent treatment ever since, stomping around. He’s 29, this isn’t attractive behavior. What am I supposed to do? When our lawn looks the worst kept in the neighborhood it’s embarrassing!