18 month old issue with belly/me

My son was cute with my belly (kissing it etc) for 4 weeks max. The bigger I get and closer to delivery he wants NOTHING to do with it. I know toddlers are going to go in and out of phases with the baby when the baby was here but I wasn’t expecting this now being 8-10 weeks away from delivery. Anyone else have any experience with this? We have been positive about big brother opportunities, excitement and always loving him. I don’t know what else to do.