If trying out the slow version doesn't wprk out for you, there's always the option of disabling sound in your settings. Assuming that this is still a problem, that is.
Well the thing is, in this lesson, I ended up seeing five times that men love women and not once that men love each other or women love each other ! Not once. And it's the same in all the "Basics" lessons I followed... Seems like people make those exercises want these straight ideas to get in our head... I'm not saying it's homophobic or whatever, but you've got to admit that seeing this five times in one lesson somehow conditions my brain for heterosexuality and implicitly tells me that homosexuality isn't natural, or doesn't even exist since they never talk about it.
No, I get what you're saying but you're absolutely wrong. This course is one of the most inclusive ones on Duolingo. We have lots of sentences that are non-hetero. All that's happened is that the underlying system decided you needed extra training on some exercises, which happened to be those exercises. We do not control that at all.
somehow conditions my brain for heterosexuality and implicitly tells me that homosexuality isn't natural, or doesn't even exist
You're really, really making a mountain out of a molehill here. Comparing getting a few heterosexual sentences with brainwashing, I mean, come on... I am non-binary, not heterosexual myself, and I don't have any brainwashing agendum.
You're at level three, with 150 xp, which means you've gone through exactly fifteen of the most basic lessons. Later in the course, you'll encounter sentences such as "Her wife is a priest" - you should see the deleted comments section on that one.
It is only heteronormative if the course exclusively offers heteronormative sentences. An inclusive course offers all kinds of inclusive sentences.
This course in particular also offers sentences such as "he loves him", "she loves her", "he cooks for his boyfriend", "her wife is a priest", and many more. It is possibly the least heteronormative course on Duolingo.
Please do not make assumptions based on a single sentence.