Consent is easy as FRIES:
Reversible. Anyone can change their mind about what they feel like doing, anytime. Even if you’ve done it before, and even if you’re both naked in bed.
Informed. You can only consent to something if you have the full story. For example, if someone says they’ll use a condom and then they don’t, there isn’t full consent.
Enthusiastic. When it comes to sex, you should only do stuff you WANT to do, not things that you feel you’re expected to do.
Specific. Saying yes to one thing (like going to the bedroom to make out) doesn’t mean you’ve said yes to others (like having sex).
The only way to know if someone wants to have sex with you is to ask. Consent is about asking, and listening to the answer.