you don't have to look. staring at straight couples kissing is rude and creepy. why stare at dudes kissing?
also, grossed out is not the same as angry or violent or offended. i've seen brutally ugly people in bathing suits, yeh it's gross, but they're just trying to enjoy the sun.
If I see two men kissing I have to have a boner? And if I have an angry one, that makes me conservative? At this point, I’m struggling to get what is going on :D
If said straight guy is also grossed out by kissing of other pairings of humans, then definitely, yeah.
I also imagine that some people are not actually gay, but rather are just worried that it might invoke something in them, which would cause social problems for them. So, to block out any such impression, they develop this grossness reaction. I used to have that, too, when I was young / socially dependent on people inaccepting of homosexuality.
I do not see why else someone should be grossed out by two male lips touching.
Nobody can stop you from thinking about cock sir, if you love cock so much you just want to think about it all day, that's fine. No need to dress it up as "being grossed out"