Was I wrong to ask?

Me and my SO have been together 7 years, I've never been one to check phones, call logs/internet history my mindset is if you're cheating itll come out one way or another and it has for me in the past probably due to my exes getting sloppy hiding it (leaving msn conversations open back in the day 😂) that sort of thing but I'm quite straight forward and prefer to be that way... if I have a problem or something doesn't add up I'll outright ask, if the persons lying after I've asked them then they're not the person for me right? Keeps life fairly simple SO ANYWAY

We have a 3 month old, never questioned my trust for him, we had a hiccup barely a year in he was on this dating but not dating site where you bid for people?? (Fake money ofcourse, I know I dont get it either 🤷‍♀️) he left it open on his browser I asked him about it, explained I didn't like it because you're basically bidding based on someones attractiveness to you, he came off, that was that we're now 7 years in, haven't had a hiccup or any reasons but tonight something just seemed so off.

He went to the toilet to shit, usually takes a decade because youtubes or plays games on his phone no biggie, I went to the bottom of the stairs and asked if he was done (a nudge to say get off your phone basically) weve gotta bath the LO, I SWEAR I heard him meekly say "I'll call you later" a small pause and then 1 or 2 words I couldn't quite make out, I asked who was on the phone (usually his parents, our friends or his sister/brother) he said "no one, I was watching some youtube video", I said "but you said I'll call you later" he walked down and said I must have been hearing things, I said honestly I swear I heard you say it (not calling him out more of a "but I'm sure?") He got defensive and said "well you must know better than me" so that peeved me alittle, I asked for his phone, played the youtube video and the voice was too high pitch "nah that's not the voice I heard honestly love" now I'm thinking and questioning myself but I let it go, forget about what i thought i heard and carry on sorting the LO, bath, bottle etc

As I start gathering her bottle and dummie up I turned the monitor on (I leave it downstairs charging when I'm heading to bed but it was unplugged this time) I noticed it was positioned on me and the LO which completely threw me out as I always put it face down when I go to bed ALWAYS the idea of being watched freaks me so I never don't put it face down and this wasn't a fluke it was placed.., my SO had gone downstairs for a smoke at around 4am last night because he couldn't sleep (stressed, funeral planning, every now and again cant sleep well anyways) LO woke me for a night feed this is how I knew he wasnt in bed, I text him while feeding her, said he was having a cig he couldn't sleep hes be back up soon, not sure when he came to bed as I sorted LO and fell back asleep before he did, so I asked if he moved the monitor and he said no, so I turned round and asked "are you doing any dodgy talking I should know about?"

He replied "No, are you doing any dodgy talking should know about" and then the rest of the night was basically little digs "here take my phone"... we both go for a cig "can I use your phone" "why wheres yours" "well I'm getting accused of cheating so I left it in the house I'm going to leave it alone", cat got upstairs and knocked baby monitor, I ran up, got the cat out, repositioned it, came back down "what happened to the monitor? Was that cheating?" I just shot him a "fucking kidding me?" look, asked how long this would carry on for and asked him not to talk to me until hes calmed down.

I probably didn't handle it the best but I asked because it all felt weird and now I'm paying for it... honestly... was I wrong? I'll apologise just need an outside opinion 😣