That's so great to hear! I knew it was your own demons and not his bad behaviour.
It reminds me of how i feel when my Other partner (the non-spouse) tells me about someone they are attracted to or had a relationship with... Doesn't matter if it's past or current or never meant to be... I feel a sinking feeling like "why are you telling me this? I don't need to know this. Do you talk about ME with other people this way?"
Then, i realize that they probably do talk about me with others... and it is probably equally flattering and positive as well as honest. We really have nothing bad to say about each other. Also, telling me about these people/relationships/feelings means that they trust me and are secure in our friendship (forgot to mention that it helps to be friends/buddies with your partner(s) - not friends-with-benefits, but buddies in the sense that you can have fun spending time together without ever getting sexy or lovey-dovey) that they feel able to confide these things in me.
Another blurb about myself you might like - my Spouse went through a period of adjustment that (long story short) culminated in a miscommunication which was fixed by sending us both (myself and spouse's other partner) the same text message that ended with "love you both".
tl;dr It is ok to tell one partner you love them within earshot or view of the other partner.