Oh that's a difficult question! Something weird can be very subjective haha.
Ah yes I have one!
[TW menstruation with details / Very Lewd]
During an evening, we had sex, an ex gf and I. We knew that she had her period but we didn't expect how fluid and liquid it was. But it didn't stop us and strangely, it made us sooo excited. She was on me, moving on my hand free dildo. And when we've done and she rised up from me, I saw my pube, my dildo and belly covered of her blood. it drove me totally crazy and when we went to the shower together, we fucked again and again until we were really tired haha. I guess I discovered a new fetish of mines this evening.