These have had me alternating between howling with laughter and being horrified! Brilliant thread!
So mine are -
The bloke I lost my virginity to, suddenly took every opportunity to argue that women "couldn't piss and shit" at the same time, it was physically and medically impossible. I argued to the contrary a few times and then I suddenly realised he wanted me to "prove" it was possible! I was out of there straight away, when the penny dropped! Thankfully we hadn't been together long!
At 18, I had acquired a very intense friend through college, who very clearly had a massive crush on me.
She had a boyfriend, I was single at the time. The 3 of us were together at his flat and it was kind of edging towards a threesome. (That was ok, as I class myself as bisexual and at that age, I was horny and up for anything!) Except, when she leaned across to free him from his boxers, she said "Mmm, Moonwoman, smell that! I love the smell of his cock"! It was the wrong time to point out that cocks shouldn't actually smell, so I gathered my stuff together, made an excuse and left. We never spoke after that!
In my 19th year, a bloke from my local, that had become a good mate, invited me back to his for a coffee after the pub shut one night. He grabbed me and started kissing me passionately! I was pushing him off, telling him I didn't see him in that way. We were laughing and joking all the while. He'd say ok, then pounce again. (I didn't feel unsafe at all, I just found it hysterical that he was trying so hard! I really wasn't into him sexually, he knew it, but was trying to convince me that I was, but that I was denying myself!) We were rolling around on the floor, me laughing, him trying to seduce me. I said I wanted the coffee he promised me. So he got up to put the kettle on, then appeared from the kitchen, minus his lower clothes and he had the biggest erection I've ever seen in my life! It was huge and just there, bobbing up and down! That gave me the immediate ick, so I made a quick excuse about suddenly having a dodgy stomach and left!
And definitely the worst one. Last ex who I was in a relationship with for over 2 years, set to get engaged, had a thing about white knickers. Me wearing them was a real turn on for him. And as I had a few pairs in my collection, I was happy to oblige, the sex was great with him and that just ramped it up.
Until one Sunday afternoon. He lived with his parents and I used to stay over on a weekend. He had a massive family, who were always all coming and going all weekend.
Me, him and his mum were all sat in the living room and I was waiting for my taxi home. His 5 year old niece was round, as she only lived a few doors up. She was showing her grandma how she'd learnt to do handstands. I looked at my ex in horror, as I realised he had the biggest hard on. His niece was wearing white knickers! I got up and went out to wait for my taxi. No amount of him telling me that it wasn't her, it was the white knickers, washed with me. I was done. That was treble ick territory for me. Even though I knew for a fact he had no attraction to children, I couldn't and didn't want to get past that.