Okay, let's get something straight about Alex. He enjoys making homonculi, in fact, it's his addiction. He promised that he'll study to become a great alchemist to find his father, but somehow fails to do proper school work because of this. That is until Layla came and straighten him out (he's now gonna attend Hikori-sensei's class)
This happened before Layla came. Apparently Alex found Jakai to be rather "beautiful (I'm talking about the worm-monster, not Tink, the cute gal with the ears. ) so he wanted some cell samples.
he later found himself in Nurse Alice's clinic again. Dog lived.
Tink and Jakai (c)
Alex and Dog (c)