OPP - Hands to yourself when we meet my parents

Alan is meeting his boyfriend's parents for the first time. His boyfriend has already warned him not to get too flirty or handsy while they're there. Alan feels like they won't be showing the parents their real relationship if they're not allowed to kiss or hold hands. He also doesn't want to feel like he has to hide who he is. He's thinking about not going. What should he do?