Yeah, people would use gay in that way all the time at my Secondary school. I remember a conversation I had when I was sitting with a friend;
Friend: Lol, those balloons are
so gay.
Me: How are balloons attracted to each other? It sure would be weird if balloons were sentient. Although balloons can be attached to surfaces and possibly to other balloons by means of static electricity, so I guess you could say that they can be attracted to each other, but certainly not romantically.
*Brief silence*
Friend: No, I didn't mean it in that way, I just meant they are bit bad like, you know, oh s**t I forgot you're gay sorry. Um, yeah I never really thought about it, I guess it is kind of offensive.
Me: Personally I don't mind, I just find it odd when people use that word like that.
Friend: It just becomes a habit, you hear it so much that you just end up saying it without thinking.
Then there was the time my biology teacher said gay in a mocking tone, but not as in a "this thing is uncool" kind of way.
We had him for sex ed, and this guy asked about safe-sex in homosexual relationships, so he said "Why, are you
gay or something?" and laughed, then the rest of the class joined in laughing.
I wasn't out to many people, and was trying to keep up this facade at the time in order to fit in of being heartbroken about ending a fake relationship I had with a gay guy who was also closeted, so I didn't say anything.
The person who asked the question slid lower into his seat, looking down.
"Haha, no, I'm not gay, haha, I was just asking because, um, you know, other people might want to know about that, and I was asking on their behalf, not because I'm gay because I'm not gay" he replied.
At the end of the lesson our teacher went on a rant about how gay sex is pointless, and how gay people should remain virgins "if they can help it", because according to him it should be an activity that happens only to procreate.
I was tempted to say "If gay sex is only pointless because it doesn't lead to procreation, then doesn't that mean that heterosexual sex where protection is used is also pointless? Since you talked about that, yet you didn't say anything about that being pointless, interestingly enough." but I didn't.
Gawd...you must live in Moronsville England. The city with the densest population!
That first person (the friend with the balloons) wasn't quite so bad...but since I am an old timer I would've thought that "those balloons are so gay" meant that they look ..happy and festive and gay. THEN I would have reacted like you and scratched my head and wondered how the other person can tell boy balloons from girl balloons - and how they know which kind are attracted to which kind.
But that teacher???? So you're not supposed to have sex more times then number of children you have? You cant have sex for pleasure. How ret*d !And asking that student if they were gay in front of the class was highly unprofessional.