Small fibs / white lies after he promised to always be honest?

My boyfriend and I have been dating for five months and have been platonic best friends for years before that. In general, I‘d say he is trustworthy, he seems so pure hearted and genuine and I just know he’s not a bad person.

I‘ve noticed some behaviors that sometimes trigger confusion and anxiety in me, and whilst I think this isn’t out of malicious intent, it’s still worth noting.

The one I‘m most confused about is the feeling of dishonesty from his side. He’s never lied about anything big: in fact, when it comes to important things I always feel rather safe and like he’s genuine. It’s more so the small moments in between, like him jokingly telling a stranger we‘ve been dating for four years instead of five months, because it sounds cooler and we‘ve been best friends for years, so it’s „similar“. When it comes to our friendship and relationship, I‘ve never noticed him lying about big things and only two times have I noticed him lying about something really small: one time jokingly (which he quickly confessed to and it was just a playful moment between us) and one time when he was sad, he denied it because he didn’t want to admit it just yet.

Aside from these two moments, I‘ve always just been assuming rather than knowing. But I just feel like I really know when someone lies to me or not, so it’s hard to believe in those moments he didn’t lie. It‘s always just small things so nothing genuinely concerning but still annoying because honesty is my number one most important value in a relationship.

He grew up in a pretty chaotic and critical household, one where he likely had to learn to avoid conflict and confrontation at all cost and maybe tell the occasional white lie to keep harmony. I feel like the origin of these (assumed) lies is mostly out of the fear of causing disharmony and also wanting to make himself look cool.

And example of today: We facetimed, I asked if he still occasionally looks at the photos of us in his wallet. He said „yes, I actually looked through them today and even showed them to a colleague!“. I can’t prove nor disprove if this is the truth, though something about it just felt like a lie - like he made it up on the spot. Maybe because he didn’t want to disappoint me, maybe he just wanted to make me smile and I feel like he could just fib about small things out of habit.

What bothers me is that we had a conversation some weeks ago where I told him that honesty is the number one most important thing for me and he promised to never lie to me about anything. Just some days later the situation happened where he said he’s not sad, onl to later say he was sad and didn’t want to admit it when I asked. He apologized and promised to always be honest about that from now on. He told me he just didn’t want to talk about why he is sad and I reassured him, saying „you wouldn’t need to talk about it, just tell me you’re not in the mood but please don’t lie!“ and he agreed.

Fast forward to today: if he lied today, the little fib in itself wouldn’t bother me, but the fact that he knows just how important honesty is for me AND promised to never lie. I really need to know my boyfriend is a person where I don’t constantly have to question if he’s telling the truth or not, and yes, even when it comes to small things.

I didn’t address it yet, out of these simple reasons:

1. I don’t even have proof of him lying, just an assumption

2. Things are already a bit shaky lately since we’ve had many relationship heavy talks

3. Accusing him would lead to defensiveness on his side and if he didn’t lie, he’d just feel like I still don’t trust him (I struggle with trust issues overall)

4. Maybe he lied out of habit, accidentally but not with ill intent and quite frankly: this wouldn’t be a huge lie

I really want to highlight that he’s a genuinely good person. I know by heart that his intentions are never malicious, that he’s just a bit conflict avoidant and that he has some avoidant tendencies but overall has a rather secure attachment style.