Season 3 Episode 4. A boyfriend and girlfriend have sex. Thrusting is shown for 30 seconds. No nudity. [34:00]

Season 4 Episode 6. It starts with a young man and woman making out and her taking his shirt off and they proceed to continue making out on a bed but are interrupted by someone knocking on their door, scene lasts about 1 minute. NO NUDITY.

Teenagers kissing.

A teenager tells her boyfriend that another girl only wants to "get in his pants".

Surgery is done on alien corpses and humans. Blood is shown on clothes and skin of characters throughout the series. When people are shot by aliens, blood sometimes spurts in small dusty-like eruptions.

Quite frequent uses of bastard, bitch, son of a bitch and shit throughout the show.

Some instances of God's name invoked. Damn is heard sometimes. Many uses of "ass"

Sometimes there are characters that drink alcohol

Aliens fighting and killing people. NOT that graphic.