SSTF

It stands for "subtle slap to face"; A moment when someone insults someone in public in a way that is evident to everyone else except for the targeted person.

If a group of people have been talking about how poor a person is, and then the person joins the group. One of the people in the group might say something like "nice shoes where did you get them from" knowing good and well that the shoes are of low quality. The person who said the rude comment just used the SSTF method.

(OTT) on the tip

when a woman behaves in a ridiculous manner, showing favor to man soley based on his physical appearance. Making the moment an awkward or uncomfortable situation.
Almost as uncomfortable as sexual harassment, hence the phrase "on the tip".

A man is giving a speech, and while he is speaking a woman repeatedly points out a positive description of his physical features. Then another guy would feel that this woman is (OTT) on the tip of the guy she seems obsessed with.