I saw this on Reddit's /r/Islam: "I think everything is halal in Jannah. Correct me if I'm wrong."
Question: Is everything halal in heaven?
The Reddit author wasn't corrected. It seems unlikely to me (how could e.g. shirk or murder be halal in jannah?), but it may be that people are inhibited/prevented from performing haram acts, along the lines of drinking wine being halal in jannah:
There will be circulated among them a cup [of wine] from a flowing spring, White and delicious to the drinkers; No bad effect is there in it, nor from it will they be intoxicated. -- Qur'an 37:45-47