That's just it dot1 - I give SO much (mostly good, honest, ahem) attention to ds1 at the moment, really try hard to make sure he has lots of fun during ds2's naptimes and reading to him during the feed times. Realistically, he's getting more attention now than he ever did pre-baby (I would get on with housework & chores leaving him to play on his own pre-baby, now I rush around like a mad thing early in the morning before dh goes to work) - so why does he get so pissed off when I spend 5 minutes of attention with ds2?! Well, yes, I know why, but still!
Or worse, when we get some alone time together that's when he throws the major wobbly completely ruining any fun we might have had.
I'd console myself that it'll get easier as ds1 gets older, but I've seen the f**king fours threads on here too...