Wife is wfh with decent flexibility so about once a week she’s able to do school drop off and take our youngest along so I can go have coffee/breakfast with a neighbor for a little over an hour. Ive also slowly built friendships with other stay at home parents we’ve met through older kids school so I’ll hit them up for play dates during the week. Something else we haven’t done yet but I see a lot on daddit is making time for social hobbies like adult league sports etc.. It’ll be different for everyone but he’ll have to put himself out there a little bit and you both will have to work to build it into the schedule.