I read a lot of articles about consent in hook-up culture, about how we should be careful when we’re with a new partner to learn about their boundaries and respect them. We talk a lot about “enthusiastic consent”, and I can see how, if you’re thinking about the first time you take someone home after a date, that would be important. If it’s the first time you’ve had sex with a person, you better both want to do it, there’s not really room for any grey areas in that regard.

However I don’t read as much about how consent changes when you’ve been sleeping with the same person for a long time. Sex when you’ve been together for a year is different to when you’ve been together for three months, and it’s very different from your first time. You get used to your partner, you know what they like. You’re used to their rhythms. It’s easier to know which buttons to press. You may start to take them a little bit for granted.

I think, in the vast majority of long-term relationships, you begin to realise that one person’s sex drive is higher than the other. I expect many people reading this will immediately know which person out of themselves and their partner wants sex more often. This situation inevitably involves compromise. Before you leap to any conclusions, I’ve been on both sides of this, and I know how both feel. I know what it feels like to know your partner isn’t really as into it as you are; I know how it feels to just feel a little bit too lazy.

If you want sex less than your partner, it might be that, for the sake of your relationship, you consent to sex less than enthusiastically. But I don’t think, in these circumstances, we should be arguing that this isn’t consent. People have sex for a wide variety of reasons – horniness, loneliness, love, revenge, money. If we start putting some of these reasons on higher levels than others, we begin to devalue some kinds of relationships – an asexual person may have sex in order to keep their partner happy, despite having no desire for it themselves. That is their choice.

So, when does compromise become a lack of consent? It’s very hard to say, and it depends on the power dynamics of each individual relationship. If one person is worried that the other may leave them if they don’t fulfil their needs sexually, that’s not OK. If one person feels physically threatened by the other – for example, if there is a difference in size or strength – that’s not OK.

Pressure is difficult to identify in relationships, though, because you can only feel it if you’re on the wrong side of it. And even if one person desires sex more than the other, it is important that both partners have equal amounts of sexual agency; that they both feel equally able to initiate and deny sex. If one person initiates more frequently, it might be important to step back and check with your partner that things are OK – simply asking the question can never be a mistake.

It is also important to remember that “no” means “no”. This is particularly important for men to remember, as they have often been socialised to regard a woman’s refusal as the start of a negotiation. We see it in films all the time – a woman who at first is uninterested in a man’s advances is eventually won over by his persistence (see: Will Smith in Hitch, Zac Efron in The Last Kiss… the list goes on). If your girlfriend says she doesn’t feel like having sex, when you do, that’s tough. Don’t ask again – trust that if she changes her mind, she will initiate. Surely you would do the same if roles were reversed?

So many friends have told me stories of their boyfriends trying to change their minds about things they don’t want to do, from cunnilingus to period sex to anal. Maybe she will change her mind as she becomes more comfortable with you, but if you’ve already flagged it as something you’re ok with, you don’t need to keep asking her. Trust me when I tell you, she will remember the time she told someone she cared a lot about that she didn’t want to do something he wanted to, and if she ever changes her mind, you’ll be the first to know.

Because that’s the thing that makes consent in long term relationships a lot more difficult than in firs time encounters – the fact that you have grown to really care about your partner. You hate disappointing them. And it doesn’t matter whether that’s not enjoying their favourite film or cancelling a date because of work or not wanting to have sex, letting your partner down does make you feel guilty. It’s really important that you never manipulate this guilt to put pressure on your partner. Every time you have to answer the same question with the word “no”, it gets harder. You shouldn’t have to ever say it more than once.

Hattie Grunewald