The only possible thing that could lead to this would be two things. 1. Belle finds out about the dagger and the Plot of Pure Evil and ends her relationship with Rumple. Yes, it’s a drunken kiss, but Rumple would’ve just poofed there and killed Will on the spot. He wouldn’t do that if she separated from him. 2. Ana is dead. Will is loyal to the people he loves, so it would be OOC for him to do that unless Ana is dead. Let’s hope she isn’t, though.
I can see Belle hitting the drinks but this….This…just doesn’t make any sense.