This movie is haunting me for ages and ages! I think this is something I saw as a kid, so I believe it couldn’t be after 2000. So I believe it is 90s or 80s movie. I remeber it was a comedy about shooting a movie, and the main actors didn’t like each other in the beginning. They had to pretend they are a couple though to promote the movie.
The scene I remember - it was some red carpet event, and the lady had a problem with her evening dress. So her partner was hugging her to secretly pull this dress up while everyone around thought how in love this couple was
It is not easy to google the move where “actors hate each other” because the most results are about the real actors in those movie, and not fictional actors. I have tried to watch recently the Soapdish, which looked very promising, but this movie wasn’t the one. So I hope you will be able to help me there! Thank you 
Sounds like a good movie. Any idea of what actors might be in it?
– BunnyUnfortunately this is all I remember about this movie. I saw it as a small kid and this dress moment the only thing that stayed in my mind
– Aldrin