Baby needs a choo choo

My twins are completely and utterly obsessed with trains. To the extent that it has effected all of us. Today I took them to see "Polar Express" at the theater. They were absolutely mesmerized, and the added bonus was Santa and his sleigh. Things just don't get any better for you if you are a 2.5 yr old boy in love with trains. But then, on the way home, we passed the local train track crossing, and what do ya know, not one, but TWO trains were going by. They panicked as we passed by, freaking out and shouting, "NO GO HOME". I can't believe I obliged them and pulled over so they could watch the trains go by. Me, the hard-ass mother who doesn't take any shit from the wee ones. I am slipping.

Whenever the boys hear a baby cry or fuss, they immediately walk right over and offer their toy trains that they insist on carrying with them everywhere we go. They say to the baby, "Here go baby, play choo choo." And so far, 100% of the time, the baby will stop crying and just stare at them, and take the train. The twins will allow the baby to see the choo choo for a few brief moments then they gently take it back and say "Ok, my turn now." I swear to God, it brings tears to my eyes when they do this kind of stuff.

And then they turn right around, 3 minutes later, and hit each other with aformentioned choo choos.

What the fuck?