Long story short I’ve been with my partner 5 years and we have a 15 month old together and he has a 7 year old from a previous relationship.
We have the 7 year old every weekend from Friday night to Sunday late afternoon and 2 weeks during the summer.
How do I explain to my partner that we need at least one weekend a month with just the 3 of us and his 7 year old son needs to spend sometime with just his mum.
I feel like I’m raising 2 kids and never just have my small family together.
Source

You bought into it.
Enjoy
Posts like this is why us stepmothers get a bad rep 🫠
Sorry but you don’t! There’s 5 nights a week you have to be “your small little family!!”
Sorry but the 7 year old was there before you? He has every right to be with his dad every weekend or even every day if he wanted too.
The 7 year old IS part of your family? What kind of mother are you 🙄
You have that Monday to Friday 😬. If my Husband said that about my child he’d be getting divorce papers the next working day.
So you have him 2 nights a week out of 7 and want him less? 🤢
If this has been the agreement between your partner and his son’s mum before you and your partner even got together, You can’t expect it to change now just because you have had a baby together. It’s completely unfair to the 7 year old. He’s a part of your family
My son have been with his partner 4 years & she’s got a little boy from a previous relationship my son got a 9 year old son & they have my grandson every weekend they have just took the 2 of them abroad for a week, sorry but they are a part of the package you knew your partner had a child, I treat my son’s girlfriends little boy like my own grandchild
He IS your family , they come as a package , I would be showing my husband the door if he said this about my son