Kid will be fine, mom will be fine, dad will be fine — a month does sound long, but it depends more on what attention you provide when you are with your partner and kids.
Sounds like he is in there 24/7 most likely spending more time than you or me with his kid over the course of the year (if you are in a regular 9-5 type of role with limited PTO) — or he'd not even mention missing a month with his 2yo.
Sounds like he is in there 24/7 most likely spending more time than you or me with his kid over the course of the year (if you are in a regular 9-5 type of role with limited PTO) — or he'd not even mention missing a month with his 2yo.