My friends wife died suddenly 18 months ago, 3 weeks after the birth of their second child; he was, shall we say, “finding comfort” within 6 months and did introduce one woman to his kids but has yet to have a relationship.
It’s been taken differently by different friends but as has already been said, it’s his journey, and aside from feeling he needs to put his kids first in any decision he makes outside of that it’s none of anyone’s business how soon or when.
It’s him who has to lay alone in bed at night thinking of what he and his sons lost and what they need to be happy again, no one else.