Learn English – negative word for an overt display of emotion

I recently discovered a friend who always believed that cheesy, corny and tacky meant (to use their words) a "pornographic display of emotion".

As in: The end of a TV show where that Dad says to the son, "I love you and I want the best for you". To them such things are "cheesy" because they're too "explicitly emotional" — but not because they're cheap or insincere.

So when they heard people say "that song is cheesy" or "the ending of that movie was so tacky" they thought it was referring to an exposed display of emotion which makes them feel uncomfortable. Not necessarily because the movie was trying too hard, and therefore coming across as fake or mawkish, but simply because the characters were sharing their innermost.

For example, this person could be at a wedding in real life, and watching a proud father welcome his new daughter-in-law to their family, describe it as "tacky" — solely because his feelings are on display.

I've explained that corny, tacky and cheesy actually refer to insincerity and cheapness, much to their surprise, but now I'm wondering if there is such a word the means what they thought other people were referring to.

Is there a word that to negatively describe an overt display of sincere (ie. not mawkish, contrived or exaggerated) emotion?

Edit: I don't think this question can be answered, as I believe looking upon such things negatively is purely in the eyes of the beholder, and not necessarily something that is objectively appreciated by a large number of people. Happy to be proven wrong, but to restate: I'm not referring to exaggerated or overly sentimental displays of emotion — just honest displays of deep emotion, period.