There are some excellent ways to understand consent. At the crux of it is that our society has led us all to believe that sex is the only exception to the consent rules.
That is, you would not force someone to do any other activity, like play tennis, drink tea, play cards or carry heavy things if they didn’t seem to enjoy it and indicated they didn’t really want to.
The same applies to sex. Sex is supposed to be fun and is to be enjoyed by the people doing it. The second this stops happening is the second you stop having sex or touching another person.
Consent means a very clear, enthusiastic yes. ‘I don’t know’ means no, ‘maybe not’, rolling away from you, recoiling from your touch, and ‘no’ means no.