No. All this stuff about fluidity is fluidly and flexibly great, but there are people are are 100% straight. I am more than 100% straight and I have been with men who are more than 100% straight. My first ex H had some gay tendencies and my second ex H was more than 100% straight. I know other men who are 100% straight.

What seems to be happening is that people who are 100% straight become 100% straight in childhood, many many years before puberty and regardless of puberty. I am not certain, but that is how it seems to be happening. People who are 100% straight have feelings for the opposite sex that are not hormonal in any way and those feelings developed very early - in kindergarten. That seems to be how the foundation of being 100% straight is laid.

It is really good to conceive of it as a continuum, something fluid, etc. etc., but not take it to an extreme: there are enough people who are perfectly straight.