How do i set boundaries with overbearing in-laws?

I could really use some advice, especially if you’ve been in a similar situation.

Let me start by saying my in-laws are lovely people—I don’t have anything against them personally. But over time, their need for frequent visits has become overwhelming for me.

They often invite themselves over or expect us to visit more often than I’m comfortable with. While I politely decline some invitations, they don’t seem to take the hint. It feels like their ideal is to meet at least once a week (if not more), whereas for me, once a month is plenty—unless there’s a special occasion. I have a busy life and other priorities, but they seem to forget that.

When we visit, they expect long visits lasting many hours, complete with a full meal. They’ve also made it clear they expect the same when they come to our home. A simple coffee and chat isn’t enough for them. On top of that, whenever we’re leaving after a long visit, they’ll pile on more invitations or suggest multi-day activities with overnight stays. Even if we’ve seen them just two weeks earlier, they’ll remark that it’s been "too long."

What’s frustrating is that their invitations are often directed at me rather than my partner, their son. They’ll call me to organize visits or invite themselves over, sometimes without even mentioning it to him. My partner understands my frustration to a degree, but he’s from the same family culture and thinks their expectations—like being served a meal—are reasonable. He’s also not great at visiting them on his own, which probably encourages them to include me more.

I’ve tried being polite and declining when needed, but they don’t seem to respect the fact that I’m more introverted and have a different approach to socializing. I feel suffocated by their constant need for contact, and it’s starting to affect how much I enjoy the relationship.

My suggestion has been that my partner visit them more often without me, but he rarely follows through on this. He prefers that I come along, and he seems to think it’s “expected” that I join him.

I don’t want to hurt their feelings, and the idea of having a direct conversation about this makes me very uncomfortable. Why can’t they just take the hint, respect our differences, and meet us halfway?

Has anyone dealt with overbearing in-laws like this? How do you set boundaries without causing unnecessary conflict? Any advice would be appreciated.