This probably won't show up right away because I'm still stuck in moderation but just in case. . .

What if you weren't home at 4:30? How long does it take him to mow the lawn? Could you come home about 10 minutes before he'll be done, looking great like you just came from somewhere fun? Maybe go out and treat yourself to something or a meal/coffee with a friend so you're in a great mood when you get there? Just a thought.