I get a lot of the Nice Guy™ syndrome. They befriend me, seem like a nice guy, we get along, become close, later he confesses he likes me, I tell him I only see him as a friend, he cuts me completely out of his life, I feel like a shit person for it. I put my trust in him, told him secrets, thought I found a genuine friend and then he pulls this shit and I'm the bad guy for it.
Some other stories, I've had a guy call me a lying bitch because I was sick and cancelled our date (it was on a Monday night). I had a party on Friday night and my friend uploaded the photos from it on Monday night. Fuck boy thought I lied about being sick and was partying that night instead, he shit talked me so much to my friend behind my back and said he never wants anything to do with me again. We only knew each other for a week and went on 1 date. Fuck boy 100%.
There was also a guy I was dating for awhile. He was sweet and charming at first but quickly turned possessive and aggressive. He would get mad and suspicious at me if I took too long to reply. One time I was at a wedding and left my phone off in my bag, he blew up so bad over it. I was so stupid for letting it go on longer than it should of because I was so attracted to him physically.
I've only been in one serious relationship and he was a good guy thankfully. I never want to get serious with a fuckboy, so I make sure to end it as soon as I see the red flags during dates.