
sorry for your loss! It never is easy to deal with them passing for the first time, and for some people it never does get easy. I like to keep the remaining parent behind in the house as usually they get happy again before the day is over.
There was a topic
here and
here about depressed little people.
To sum everything up, keep his fridge well-stocked, praise him two times if he does something good like exercise.. candy and fruit are great for praising as well to raise happiness. Perfume and cologne will raise his happiness as well, the perfume being more effective on a male's happiness. House upgrades will also raise happiness, but if you're just in the first generation you should probably save your money first as much as you can for a few generations in case anyone gets ill. The more money you save, the more money you get in interest so the rich get richer!
You won't see his happiness bar raise too significantly in a short amount of time depending on how you're raising it. Just give it a day for him to think about his wife and get happy again.

If he does misbehave, try to avoid scolding them or using the salty candy. Imported candy might also make them more sad, the result is random.
Best of luck with your little family
