In January of this year, OH asked if we could switch to BT from Sky, it was cheaper and we weren't using most of the channels from Sky so I agreed. At the time, they were doing a £150 Mastercard as an incentive for switching, I asked him to check Topcashback as I know they usually do good deals for things like utilities and sure enough they were offering £100 for new customers. We agreed that he could have the £150 Mastercard as he wanted new tyres for the car, and I would have the £100 cashback once it tracked.
A few weeks ago, I asked him if he'd had it yet and he said it had tracked but he hadn't received it. I know these things can sometimes take a few weeks so I left it. Fast forward to today and I was going to ask him when I got home. He is currently in bed with a migraine so I had a sneaky look on his Topcashback account (I know, I know). Sure enough not only has he received it but he's also claimed it.
I feel angry that he's claimed it as well as having the Mastercard money when we agreed to share it equally. I know if I ask him he will tell me it hasn't gone into his account yet but I don't know how to tell him I know without him finding out I looked on his account. I know I shouldn't have and I don't usually do stuff like that, but I was just curious.
AIBU to expect him to pay me back what is mine and how should I approach this conversation?