I mentioned in my other reply that my hiking group hugs when we meet, which started as a joke when the women did, then stuck. Now, when someone new joins you can feel the emotion of missing out when they arrive, and the acceptance when it happens as they leave.

Next time a mixed gender group meets, and the women hug the women and men, etc, start a ridiculous laugh and pretend to hug one of the dudes. If he does, you may have started a trend.