A different interpretation

(I will start by saying that I haven't seen this movie in years, so I'm sorry if I can't back up my ideas with a lot of examples and such).

When I saw this movie for the first time, I hated it with all my guts. Apart from the fact that I thought it trivialized mental illness, what truly shocked me was that people were charmed by the relationship between the two leads: 'they're so quirky! They managed to find the perfect match despite being *beep* up!'

In my opinion, Pat and Tiffany's relationship seems incredibly toxic. She manipulates and lies to him throughout the whole movie and, inexplicably, Pat doesn't seem to care one bit when he finds out, professing his love for her instead. That seemed like a huge plot hole to me.

A few days ago I was talking to my bf and this movie came up. He said he loved it, and when I expressed my criticism, he said that the fact that their relationship is so *beep* up is exactly the point of the movie. The rom-com 'framing' (sorry, I can't come up with a better word for it) is light-hearted and quirky because the story is told through the eyes of Pat, who is obviously a bit dysfunctional, and therefore what seems cute and romantic to the leads should appear *beep* and toxic to the viewer. It's a rom-com in their eyes, and their eyes only.

My question is - do any of you guys share this same point of view? After thinking about it, it does make a lot of sense and it would probably make the movie understandable to me, but I'm not sure if it was intentionally set up that way and most people didn't 'get it', or if it's just a lucky coincidence.