Playing D&D 5e.
I asked a similar question on reddit, so I will copy the summary of events from there:
Okay; I admit that part of what I am about to say is fairly absurd, because we do allow silly things in our group. It's also really just a rant, so apologies, but I do want to know whether or not we overreacted in response to the GM.
Some background: We're a group of level 3 - 4 character at the moment. Early on, a neighboring town was wiped out by an necromancer mayor who used my character's love interest as a human sacrifice. This set my character out on a task of getting the resources together to revive her. He asked the mayor of his own village if he could use the land for his own purposes, and rolled high enough that the mayor agreed (yep; our group basically took control of an abandoned town and has been working on rebuilding it). Anyway, clearly my character has become obsessed with the task of reviving this girl.
Today we were dealing with a tiefling that was enchanting us. Even a roll of 18 did nothing to protect us, and I think even a 20 was only a minor save. Fine. We take on a mission, essentially for free, because we're so enamored by her. We leave the area, and my character, with fairly high wisdom and intelligence, who has been able to talk his way out of most situations, was not able to be aware that ANYTHING was up. He didn't even think to question why he took on such an absurd quest. Fine. Maybe some kind of really funky magic was going on, but I accepted that. Moving on, he had someone make a silly roll about his sexuality and it turned out that (and he wanted this to remain canon) he was ONLY interested in unicorns.
This brings us back to the Tiefling and the start of the conflict. The unicorn-sexual pointed out to the GM that if the character only had a thing for unicorns, he should not be affected by the tiefling. That made the GM say that we all saw our deepest desires. But that means my character should have seen his love interest alive and well, which would NOT make sense and if I had said that to other members of the party they would certainly have been WTFing.
From there, the GM decided that either I go with it or my character was no longer interested in the love interest and only in the tiefling. And at that point everything went to hell and that was the end of the game. I get that some loss of agency is fine in a game, but seriously, I think that was unacceptable. The GM set up a situation that in order to keep the story moving along as he wanted, too many things would have had to make no sense.
Of course, the biggest issue is that the DM used a vague reason (enchantment, spell, I don't even know) to take away our agency, even if only partially, rather than just limiting the decisions we can make or suggesting to us that our decisions should be influenced. What is a good way to point out to the DM why we had such an issue with him doing that?