well apparently not.
first, steam activity isnt really chronological, unless ur sure he didnt play cod at all yesterday, then its hard to tell if he did load it up after he supposedly went to sleep. even if he did play, y didnt he tell u? maybe he felt u were being nagging? i dunno how long u two had been talking for. i dunno how u react to being told that he wants some game time alone. maybe he couldnt sleep and got back up to play. either way, there r underlying issues still present that u two need to work thru.
This was my thought exactly. If I tell somebody, alright bye I'm going to bed, and then I decide, nah I'm going to get up and make a sandwich and mess around on the computer for a while instead, does that make me a liar? Technically yes but christ I mean is it that big of a deal?
I mean when I'm in a relationship I don't feel the need to tell my so every little thing I am doing just so they are aware. If I'm tired and I don't feel like chatting I might even say the same thing, that I'm off to bed. I may game a bit or whatever beforehand, but then I'm going to bed. I just take a bit of downtime first. This could have been what he meant. Not necessarily "I'm going to bed right this second".
I could understand you being upset if he lied about something to go hang out with somebody else or go do something without you, when he should just be honest and tell you those things. Totally get that. But playing video games before bed doesn't seem like a horrible lie to me. Or even an intentional lie. Or not even a lie at all if he was planning on going to bed and then got back up or whatever. Was he supposed to text you back and say, "Nevermind I got back up to play some CoD, just so you know"?
Sorry if this comes off as rude but if you want honest opinions, I just think you're way overthinking this. But by all means talk to him, I mean it's your relationship and if it bothers you then let him know.