For me it was quite an unfortunate situation.
I had a crush on this dude from my local gym, at first it was a "Ok, he's str8, nothing can happen", but then as we grew really close friends I got confused in the situation and thought something could happen. At one point, I decided I had enough of thinking about it and just told him.
For my surprise he didn't answered the way I though a str8 guy would do "Hey man, I think you're mistaken, I'm straight and don't do dudes". He stared at me and said "But, what do you want?" I was completely shocked by this and told him I just wanted to let him know I liked him, a lot and for that reason I would have to quit our friendship. He then proceeded to tell me he didn't wanted it to happen like that and "let me go".
So this toxic twisted situation started happening between he and I from that moment forth. I would ask him to hang out or have dinner, to what he would agree to do so, but then, when we finally sat at the restaurant or place we planned, he would go silent or cut strangely the conversation. He would text me days later asking how I was or how the office was going and then cut communication again. I even gave him christmas presents and he had no trouble with accepting them (not that he had something for me in return).
Eventually I decided to take an initiative to answer his question from the day I opened up my feelings "What do you want?". So I asked him to have breakfast with me and then I would proceed to let him know I started having "feelings" for him and that I'd like to date him. When I boarded the subject, he answered with a simple "No", to which I replied asking why. He said he didn't liked dudes and that he only considered me a friend.
From that day we only hung out only once and it was a really awkward situation, that time he asked me to go for dinner (to pay me back from "new year's celebration dinner" I payed for). Once more I miss-understood the situation and we argued. The next day I offered him a sincere apology, to what he answered "this is situation is getting too tense".
It had been more than two years from this weird situation and decided I would give it not even one minute more. it's been two years now and I haven't heard from him again.
My story was quite complicated, but what I really want to say is, do not waste your time having crushes or falling in love with str8 guys, there's plenty of fish out there to encapsule yourself in a toxic situation.