When you say "only two feeds a day", are you giving him a cup or bottle feed at some point other than your morning and evening feeds? I would expect him to be needing at least one more feed at some point, and quite possibly two.
I don't think giving the extra feed when you are around will confuse him. When DS was around that age I was back at work and doing morning and night breastfeeds, but would do a third daytime breastfeed at weekends or days off with no problems.
My DS is only 7mo but I've been leaving him with his auntie for a few hours from around 3 months so I could do the odd bit of work.
We found that, even that early on when with me he'd be asking for food every 2 hours or less, he'd happily go 3-4 hours with her because I wasn't there, and he couldn't smell the milk.
I would think that if someone else is looking after him, a cuddle would do instead as there's no temptation for milk - this works well for DS still. (although he was a bit confused when his auntie had a friend round who was still BF and she gave him a cuddle! )
My guess would be that yesterday he might have been feeling a bit off colour or something, but even if he regularly wants it, don't worry. DS won't nap for me without a BF, but will for his auntie.
That makes sense. I guess I am just getting anxious at the thought of leaving him for a whole day with someone else. I will see how today goes and if he wants a feed I won't stress about giving him it. I wish I wasn't under so much pressure to work but such is life.