Negative-connotation word for someone who is straight-edge?

What is a word for someone who doesn't party, doesn't do drugs, doesn't drink, doesn't have sex, etc.

Preferrably with more of a negative connotation.

Edit: I'm looking to use this in a self-deprecating context

Solution 1:

"Square"

Urban Dictionary:

4. A boring person.

Dictionary.com:

7. Slang. a person who is ignorant of or uninterested in current fads, ideas, manners, tastes, etc.; an old-fashioned, conventional, or conservative person.

Solution 2:

Goody Two-Shoes:

• Often used to describe an excessively virtuous person, a do-gooder.

Killjoy:

• A person who deliberately spoils the enjoyment of others through resentful or overly sober behavior.

Holier-than-thou (Goody Two-Shoes) and Party Pooper (Killjoy) are often used in the same contexts.

Solution 3:

strait-laced (adj.):

1. Excessively strict in conduct or morality; puritanical; prudish

'strait-laced censors'

Source: Dictionary.com

2. Having old-fashioned and fixed morals, especially relating to sexual matters

Source: CDO

Solution 4:

I'd say a puritan :

• A person with censorious moral beliefs, especially about pleasure and sex. (ODO)

Puritan refers to Puritanism and should not be confused with

Purist:

• A person who insists on absolute adherence to traditional rules or structures, especially in language or style.