Being gay is not only about having sex with the a same sex partner. Straight guy (even girl) can have gay sex without being gay themself because it can be just that, sex. It's why 'kiss' can have a 'highter' meaning than having sex for some people and it's seems to be the case for the seme. Obviously, we all know that he had strong feeling right of the bat for the uke but hey, he had the right to be coufuse about is own feeling. :)
"Straight people having gay sex" is maximum cope for people with internalized homophobia
I think the word gay has become too broad to define it by having romantic feelings for a same-sex partner. Someone may consider themselves to be gay even if though they are only homoromantic but not homosexual. The same could go for someone who is not homoromantic but is homosexual. This may be a bit confusing so I'll provide an example. Say someone considers themself to be gay but they are homosexual and aromantic. They do not have romantic feelings for anyone but are still gay in the sense that they have sex with the same sex. I think being "gay" has more to do with how you identify than anything else.
Fellas, is it gay to kiss after having anal intercouse with your same-sex cooworker?