I'm okay with my partner seeing other people, but he's secretive about it, which makes me feel like he's cheating

Do you consider it cheating when your partner hides the fact they have other partners? My partner is poly but he often hides when he's started a new relationship or he hides how serious the relationships are and this has really damaged my trust in him. I'm not sure if it can be considered cheating since he is in fact poly but I don't think it's okay for him to hide these other partners? What is your opinion?

There is no standard "cheating" that you can measure various behaviors against. For some people, this wouldn't feel like cheating - but it feels that way to you, and it's not a dynamic you want in your relationship. That's what matters.

Talk to your partner about this issue. Tell him that he does not need to hide his relationships, and that when he does, it feels sketchy and cheat-y. Let him know that you're okay with things as long as they're out in the open.

Ask him if there's anything you've done or said that makes him feel like he should be doing this. Figure out why he seems to be more comfortable hiding and downplaying his other relationships. Work out a way that's safe and comfortable for both of you to be open and honest.

If he's not willing to do this - if he denies that he's been hiding things from you, or says that's just how he wants to do things, or insists you're overreacting or have no right to be annoyed when you find out he's been lying by omission (or straight up lying) - end the relationship, because he's not someone you can be in a healthy polyamorous relationship with.