I have a few suggestions, but for most of them it is not the main theme, rather just side content.
Crimson keep - would be probably your best shot. Most scenes are with regular monster girls, however there are quite a handful beastwomen mixed in as well : fox, dog, wolf - based. There are no marriages so far, but instead there are consensual contracts estabilished between the main character and the other characters, which are not that far off from marriage. The theme of the game is mostly wholesome if that´s what you´re looking for.
Venus Blood chimera - Basically there are three characters and one of them is a beast woman, so around third of the game content is dedicated to her. It is bdsm and brainwashing themed though. Kind of hardcore scenes overall. The sequels of this game have some beast woman content as well, but a lot less than this iteration.
These games I´m not that sure that fulfill the conditions:
Sequel series - I personally found the series way too grindy and not that fitting to my tastes (light femdom), but there is a marriable fox girl between the characters I think. Also if you do plan to play the series you should read up on the play order since part of it is banned from this site and not available for download from here.
Dungeon of lulu Farea - I´m not sure if this qualifies. There is a rabbit- girl and a fox girl that might be counted as beastwoman, I´m not sure.
Nanairo Reincarnation - A VN with a romancable fox girl, also not sure if this counts.
