HELP MY FRIEND DISCOVERED OMEGAVERSE AND NOW THEY'RE USING THE WORD "HEAT" IN A DIFFERENT WAY

How do i explain to my friend without sounding offensive, that it weirds me out that they're using the word "heat" to describe their mood. I'm dying here, I don't know what to do. They've been saying they're in heat almost all the time and I don't know what to do ineedhelppleasewhatthefuckamisupposedtodo
Also how can I properly educate them about the rape trope in yaoi bc I think they're liking it more than they should and calling at as the "top being a sadist" when it's not like that...