Yes.
If you and your lady smash 3x/day when y'all dating, it'll be 1x/day or 2x/day when married.
It's natural. You get older, more responsibilities...life happens.
The amount of sex you have will vary from couple to couple but the volume will go down, even if just a little. Adding new quirks to the bedroom and changing shyt up can reverse the decline.
Facts. We got our little one out the house last year after being at home for her first two years. We thinking we would get it in more since the baby is out the house.

We did at first. Really more two a days.

We always have stuff going on, but that’s no excuse to not make time. Our couples therapist is a sex therapist as well. We did two sessions this R&R. Honestly, in eight years we never talked about sex. It was good to finally talk about it.

I learned some things about my Wife plus we are more in sync.

My Wife’s best friend is only having sex once a week. Her husband is mad. They been together for 13 years. Dude probably has a side piece. She can’t ever get in the mood and he doesn’t know why. Plus he can’t be honest with his Wife nor their therapist. They are “happy” but if she let the cat out the bag more, they might be happier.
