Fantasy football, the husband killer

Ladies! How do I let my husband know he can not sit on his phone all day and watch football? We have a 4 month old and a almost 2 year old. I used to let him have the day when we just had one kid and it was fine but now we have way to much to do for him to just check out. He’s extremely sensitive about this, he loves football and is in 3 Fantasy leagues with a lot of money on the table. How do I approach this without it becoming a huge argument? I’m ok with him watching his team play but not every game all day long.