He seems suspicious of me all of sudden

The other day I went out with my mum and ended up being longer then expected. I came back and my SO was asking why it took so long, also said my mum was acting weird?? I was like are you being serious?? It's my mum!! Apparently women always calculate how long it takes men to get somewhere and back, I've never done this in my life and he seemed pretty pressed about it.

Anyway I need to run some important errands (I don't tell my partner everything, its not anything new alot of people do it). So I gave him a brief of my errands and he asked what time I'd be back and when I told him hes asking why its going to take so long 😑😑😑

I never question his schedule or ask why it takes so long for him to go places, I take his word for it and get on with my life.