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I wouldn't read too much into the turning into another person. When I go to social outings, I do the same thing. I become really bro when I'm with athletic types, really chill around the outdoorsy camping ones, super nerdy around highly educated people, and me when I'm with my girlfriend alone. She recognizes it as me just wearing social masks to chameleon into the setting so I don't ostracize myself or look like a snob. It's just a social practice my ENFP brother taught me to employ. I think social types just tend to naturally do it better than others.