Marriages

To marry an eligible woman, you have to meet her minimum sex skill requirement, impregnate her, and end the season owning a wedding ring, having positive disposition and having committed 1 or fewer sex crimes. Some women have additional requirements or disqualifications.

C41/slave
Own C41 and don't screw around with too many of the other slaves in that dungeon you found her in.

Shinoa
Trick her into streaming your sex.

Val (blonde drunk)
Do not touch her roommate.

Britney (babysitter)
No special condition.

your own mother
Find your own mom and impregnate her. Requires the use of a start wherein you are the offspring of one of the characters.