Causing your sexual arousal or physical attraction to
dissipate (the sexual analogue to
buzzkill or
downer.) Literal meaning is "causing to become flaccid", but can also be used more generally to indicate loss of interest.
I was so turned on seeing that hot guy
walk in, but his racist comments were totally
flaccidating.
Yeah, she was sexy AF but her breath was
majorly flaccidating.