The teenage years can be a trial for many marriages. To be honest, I'm surprised your 13-year-old daughter wants to share the sofa with you in the evenings. Most teenagers are locked in their bedrooms, glued to a phone or a tablet. You can console yourselves with the fact that it is a temporary situation. By the time she is 16 she will be much more interested in her own love life than yours, so hang in there.
In the meantime, you should do three things. The first is to put a lock on your bedroom door. For a lot of parents this feels counterintuitive because when their children were small they left their bedroom door ajar so that they could hear them if they cried in the night. There is no age at which parents stop worrying, but seriously, by the time a child is capable of texting you to bring them some juice it is safe to insist on privacy in your bedroom. They will not think twice about locking you out when the time comes.
The second thing is to have a chat with your daughter. At 13 young people are just about getting to grips with their own sexuality, and in the same way that it can be disturbing for parents to think about their children becoming sexually active, it can be disturbing for a child to realise that their parents have sex with each other, and she may, consciously or unconsciously, be trying to prevent that from happening.
Talking about sex and sexuality with a 13-year-old can be pretty awkward, so choose your moment. A longish car journey - with just the two of you - is always a good option. Sitting side by side takes the pressure off by eliminating awkward eye contact and giving you both space and time to think and to talk. If you can normalise openness now it will make the next decade infinitely easier for all of you.
Finally, you and your other half need to be creative with your scheduling. Whether you wake up earlier in the morning or grab a couple of hours when your teenager is out at weekend activities, you need to identify times when you can prioritise your relationship. If you have parents who can stay over, try staying the night in a hotel. It doesn't have to be fancy. It's not as spontaneous, but the anticipation becomes part of the foreplay and you can pack for a night of fun. Fresh sheets, a minibar and complete privacy is worth every penny.
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