A pince-fesse is a slang term for formal “dinner” / “reception” / “gala”. We have several ass-related terms to describe the art of (decent) behaviour (balais dans le..., cul-serré, …) 🙂

In your context : J’en ai marre de tout ça. Les journalistes, *les trucs officiels,* les discours, les salamalecs avec des gens dont j’en n’ai rien à foutre. C’est lourd.
<< trucs officiels >> is quite a pince-fesse (when you can eat there !)

True, a “pince-fesses”, is a kind of formal reception with drinks, wine & cheese stuff, where you meet various officials. But if you think to the litteral meaning of “pince-fesses”, it is significant: an automatic translation would give “ass-pinching” and seems to be unrelated to the previous description.

However, when some people use that “pince-fesses” expression, they want to convey the mocking idea that this could be a place when you may meet some sexually interesting person. Generally speaking, this is a way to give a derogatory description of this type of official meeting: obviously the meeting will be so boring with so many uninteresting people that your interlocutor is mocking you by using that pince-fesses locution, because this is precisely the place where you are assured that you will not meet anybody interesting, let alone a possible sexual partner.