One of the most dangerous things in the world is not being able to say no to people because you don't want to upset them or dissapoint them. This will completely ruin your life in every way possible, at work, in your private life, your sex life and your friendships. It's a way of removing your own consent in your own decisions and go against your wishes, it is always a crime against yourself. Let yourself have a say. Upsetting people is better than traumatizing yourself.
The worst thing about it is that if you do it enough times, you will genuinely have a hard time stopping because you won't be able to tell what your own desires are anymore
I'd also say, decent people, people who are worth being friends with, will want you to express your boundaries.
Not just because it's better for you, but because by not doing that you're essentially forcing them to guess your boundaries and enforce them on your behalf, so as not to accidentally hurt you. Which is an unfair burden to place on them.
Like, to give a very common and relatively minor example, this is why saying “whatever” when asked where you'd like to eat is such a universally acknowledged Annoying Habit.
Because it gives the impression of making the task of choosing where to eat easier, but actually just ensures that the rest of the group now has to not only make a choice about where they want to eat, but also take the time to try and predict where Jessica might want to go and privately blame themselves if she can't find anything she likes.
Good people will want you to willingly consent to the stuff you do together (sexually or otherwise) and anyone who is happy with that consent being removed— by you or anyone else— is not somebody you should be hanging around.
