Introverts aren't necessarily shy and quiet and antisocial. These are stereotypes, often exaggerated ones. Social introversion and extraversion aren't the same as being a socionics introtim or extratim, that's an MBTT dichotomy. You can easily be a social extravert and a socionics introtim and vice versa. Besides, introversion is simply characterized as whether you gain or lose energy from social situations and how comfortable you are with new people. The longer an introvert knows you, the more he will open up and appear extraverted, and the less energy you will rob from him. Introverts can even throw parties - occasionally. An introvert probably won't throw many parties in a short period of time, and they tend to be smaller and more relaxed, with the same small group of people invited every time.

Some exaggerated extravert and introvert subtext.

E: I talked to 12 strangers today! Now I wanna have a party!
I: I had to talk to 12 strangers today, I think I'm gonna have a quiet night at home.

E: I really wanna hang out with Friend A. [calls Friend A, who is unavailable]. I guess I'll hang out with Friend B.
I: I really wanna hang out with Friend A. [calls Friend A, who is unavailable]. I guess I'll wait for another day.

E: That party was awesome! I wanna go to another one tomorrow!
I: That party was awesome! But I'm mentally and emotionally exhausted. I think that fulfills my social quota for the week.

E: I haven't done anything social in a long time. I need to hang out with someone NOW.
I: I haven't done anything social in a long time. [shrugs] Eh, they can call me if they wanna do something.

E: [tells deepest darkest secret to someone he's only known for a month]
I: [refuses to tell deepest darkest secret until he's known you for years]

E: I'm having a quiet night at home, so I'll only call my best friend and we'll chill.
I: I'm having a quiet night at home. Nobody better fucking bother me.