Well, my Dad walked Apollo today, and Apollo was good and tired, so I thought this would be opportune timing to socialize him with Zeus. So we did. We let Apollo sniff Zeus, and then they started 'kissing' each other. Is this normal? Also, would it be normal for Apollo to want to try to groom Zeus? He was sniffing Zeus' hind quarters and then trying to groom him as if he were grooming himself. Insight?