The point at which a person becomes highly open or agreeable
after drinking copious amounts of sangria
It may also refer to your perception
of them at this point as well if you have been keeping up glass by glass. In this sense, it's close to the same effect as beer goggles
YOU: "Wow, it may just be all of the Sangria I've had to drink, but I think you are super sweet!"
ME: "Thanks, but I think you're just being sangriable."
YOU: "No, you're hot."
ME: "I'll drink to that!"