Tighter than mosquito pussy 

This phrase uses a non-existent form of genitalia as a vehicle of hyperbole to convey the idea that something is insanely and impossibly small and tight.

I can't get any stock tips from these rich bastards -- their lips are tighter than mosquito pussy!

Tighter than mosquito pussy by C'est Logique July 22, 2011

Tighter than a clam with lockjaw 

firmly fixed in place

This motor is locked up tighter than a clam with lockjaw

Tighter than a clam with lockjaw by Gimpler June 1, 2010

Tighter than a Cat's Ass 

Intensely tight to the point that entry seems impossible

"Due to the visit of a foreign dignitary, the police had the city locked down tighter than a Cat's ass!

Tighter than a Cat's Ass by Mr. Jameson September 14, 2010

Tighter than twats 

A phrase used to define something that is outstandingly magnificent or "cool", obviously surpassing the extremity of the situation in which the words "tight" or "tite" are used.

Although the tightness of a twat may very it is assumed that we are speaking of virgin twat unless, of course, you change the context by adding the name of someone who is not assumed to have a tight twat. (See example 3)

When using this phrase all sexual connotations should be ignored and the phrase should be used to express ones awe in something rather then being regarded as "dirty" or "perverted".

"Holy balls! The new album by Breathe Carolina is tighter than twats!"

Did you see that?! It was tighter than twats when Becky punched Jessica in the face, knocking her front tooth out!

Well that was about as tight as Tanya's twat. We all know she's a whore.

Tighter than twats by aerickson293 September 2, 2011

Tighter than a Nuns cunt

Something that is extremely tight. Usually referring to nuts and bolts on a car.
Most commonly used in a mechanics garage and is the result of many skinned knuckles.

Those bolts are Tighter than a Nuns cunt.

Tighter than a Nuns cunt by Paul Loose November 15, 2007

Tighter than dick skin 

Extremely tight, often in reference to the fit of clothing.

This Yanni t-shirt is tighter than dick skin!

Tighter than dick skin by L Wrong Hubbard January 14, 2017

Tighter Than Dick's Hatband 

An old southern idiom. Could be used to identify a place that is empty, a person who is wound up, or any number of situations where the word "tight" is used. Nobody seems to know who Dick was. Apparently he had a tough time keeping his hat on his head.

I went and checked that place you told me about. They've closed up tighter than dick's hatband. Have been for years.

Tighter Than Dick's Hatband by kiteless. June 12, 2013