Is it weird to keep the t-shirt of an ex?

As opposed to being honest with them for my own inconvenience? I'll be sure to jot that one down for future use!

I'm not suggesting that lying is a good thing, nor am I taking any moral high ground. All I'm saying is that in certain situations it'd be ignorant for anyone to suggest that lying cannot be practically beneficial.

In this situation, it'd be very easy for someone to kick off because their partner has something belonging to an ex, and lying about where that something came from saves a hell of a lot of unnecessary ********.

It's a white lie about something little; if it was about something that actually mattered then honestly is always the best policy, both for the integrity of the relationship and for the absolving of any guilt. But over where a shirt came from? Small fish, it doesn't matter.

Let me put it this way: if the shirt came from River Island, but OP said it came from New Look, is that any worse than if it came from an ex but OP said it came from New Look?
If we're discussing principles of morality then a lie is a lie, right? It's still dishonesty because OP wouldn't be being truthful about where the shirt came from. But why does the shirts' origin of any importance? It's completely irrelevant to the relationship.

This is the level of ridicule we're at, because it really doesn't matter where the shirt came from. It's completely insignificant in the grand scheme of things, and certainly isn't on the same level as, for example, lying about sleeping with someone else.

So yeah, I'd much rather lie about something completely insignificant for both my and my partners' convenience than to open a can of worms over it. You can paint it as immoral as you like, but you can't deny that it's far more beneficial for all involved than potentially making a mountain out of a molehill.

I've already said that I'm not condoning perpetual dishonesty, and unless you're a saint then there's no way you can look me in the eye and tell me that you've never told a white lie (because if you ever have told a white lie, it would make you a hypocrite for coming down on me for this).

Edit: of course, the length of the relationship and how you think they'll react should also factor into the equation. If you've been with them for long enough, and they're mature enough to not make a big deal out of this, then being honest is probably the best foot forward. But for a new relationship? Hell no, you don't know how they're going to react. So placate them.