mermaid clock 

It is when an unattractive girl/woman becomes attractive to you because you're very desperate or horny. You live with an ugly girl for a long time and all of sudden she starts becoming attractive to your eyes due to the fact that you have not it in a long ass time.

Expression inspired from "How I Met Your Mother" by Barney Stinson: "Evey girl has a mermaid clock

Some guy: Dude check out that ugly girl!
horny friend: Damn dawg shes looking fine, Im ready to dip it in.
Some guy: dawg you're disgusting...it's prolly cause you're being affected by this girl's mermaid clock.

mermaid clock by djily02016 December 7, 2010

Mermaid Clock 

A given time before you realize that you wanna bone a female that you don't have any sexual or romantic feelings towards, even the most unattractive chick you see daily can in-fact have a "Mermaid Clock"

Dave: "yo look at jessica ?" Cam: " yeah she's ugly asf" Dave: "dude wait until she hits her mermaid clock"
Cam: "what's that dude? Dave: "It's when you hang around her so much you start wanting to bone her even if you don't have physical attraction towards her"

Mermaid Clock by HeyWOod_JablOmE June 27, 2021