Well, here we go!

10. They're both alike (gentle, etc.)
9. Lil Tyke loves Leighanne as much as Brian
8. As Leighanne could confirm, they're both loveable
7. They're both in good shape (hehe)
6. They're both young
5. They enjoy each others company
4. They're both small for their age!
3. They love each other (puppy love!)
2. They get along well

And the number one reason is.......(DRUM ROLL PLEASE!)

1. They look SO cute together!