Great question.

I’ve been in this position before, and it’s super hard. And guess what, even when you have a primary, it’s hard to be able to determine what the boundaries are and what demands are appropriate. 

I want you to consider reframing the issue here. Instead of keeping yourself in check, let’s think of it as how you can best communicate the things you feel would make the relationship fulfilling.

It’s so hard for me to be able to articulate my needs to partners that aren’t my primary sometimes because it’s a lot of worrying over being demanding or being a wet blanket or being “selfish.” So, I definitely feel you there.

But, I’d say the first thing to do is to talk to your partner. Go over the degree of involvement you both want in this relationship, go over your expectations, go over what you feel your needs are. It’s hard and weird and vulnerable. But, I promise the pay-off can be spectacular.