The tentacles could be the protagonist's, or one of the other main characters'.

One of the main concerns of the game should be concealing the taboo against a risk of discovery.

The main characters more or less explore a vanilla relationship, possibly harem(Or reverse-tentacle-harem)?

They progress through stages of trust and experience with eachother 'unlocking' more scenes and positions.

The 'recipients' aren't mindbroken/hypnotized/coerced to like tentacles, but may be scared at first until curiosity gets the better of them.

I prefer non-VN entries, but I'm so starved for anything like this, I can't complain if that's all there is.

I can enjoy fully-text games, but I need some kinda GUI.

MUST have a sense of humor and follow community guidelines for acceptable content.