I do suppress my feelings and avoid conflict, due to previous relationships and being gaslit in the past
I can see why this would happen and understand why (I've done it myself too), but supressing feelings and avoiding conflict is precisely what makes a person vulnerable to abusive behaviours, including gaslighting. This issue with the photo might be a turning point for you.
Expressing your feelings isn't rocking the boat. It depends how you do it. If you start playing games like burning it/seeing if he notices, that rocks the boat. But any worthy partner, if you tell them calmly that they're doing something that bothers you, will listen to and respect your feelings. It doesn't sound like he does this.
But currently, you're not respecting your own feelings. You're looking for external validation. You need people on MN to tell you that you're right to feel the way do, or that they would feel the same as you, before you think it's 'ok' to have your feelings. But it's always ok to have your feelings; they are what make you who you are. They are your heart. Your feelings are the only thing that matter. If you only do things/spend time with people with whom you feel great, how do you think your life would be, in comparison to spending lots of time with people with whom you feel you doubt yourself?#
Feelings are all we have. You could have a million quid and live in a mansion with cocktails served all day by your pool, but if you feel like crap, none of it means anything. Let your feelings lead you. Currently, you don't respect your feelings. You don't listen to them, believe in them, value them. You're asking other people if your feelings are ok or not: they are. They are you. Respecting them is respecting yourself, and if anybody makes you feel that you're rocking the boat by respectfully expressing your feelings, they're not good for you, because your feelings are lower on their priority list than you shutting up about your feelings.