Farmer gets to fuck their mother and, depending on gender, join her along wither MC's sister Kat doing some prostitution.
Noble gets to bang their mother and can have a 3some with her and Tish later on.
Templar can rescue the demon woman from the hell dimension they open the portal too, she's the women from the start of the Templar origin that's been transformed.
Thief gets a BDSM scene.
Soldier gets to fuck twins, twins are male and female not both same gender.
There is also some flavour text throughout but nothing huge. Farmer has the most content with the mother and her prostitution. If you get her to stop you have to keep her happy sexually. She will also visit the castle.
All origins get the sister companion so all have access to incest. She doesn't appear until later in the game though, Katelyn for those that wonder.
Male is by far the most vanilla route although a lot of the women have the option to fuck others, some of it unavoidable, so don't be expecting a harem just for you. You can pick 1 to marry at the end, the rest go their own way.
Female has a shit ton of kinks from monster gangbang to beastiality to pregnancy fetish. Emek's rest gets a HUGE pregnancy scene that is both full of cock and one of the most romantic things i've seen in the game.
Clawyn is the best companion to go for if you want a more romantic relationship with a near fully faithful girl. I say near fully because she is involved in a couple of 3somes with the MC and Tish ... and I think Ruk Ruk if I remember rightly.
Meredith is the worst option to go for. While she is sweet as cake she is also horny as fuck and takes dick like it's going out of fashion. Even Ruk Ruk gets less cock than her and she is up for pretty much everything.
The only companion close to Meredith on the horny scale is Succubus but, well, she's a Succubus. Fucking all the things is kinda what they do.
Tish gets around but not much.
There are some girls that only fuck the MC but not companions. Some, like the castle maid, you can get pregnant.
You can also turn Zent into a girl for 1 scene and bone him.