I finished the game on Wii&DS.
So...
What you have to do is get both of them to eat from your hand (individually) and then drop
them near each other. That should work.

Forgot to say if it wants to... you know do the same thing to get the girl and boy weasel
to bond. Then drop them near each other . That's what i did anyway.

Yello Goodbye!!

ok you get two weasels to have a baby,get 3 hearts with the baby and drop it near the
mouse!

So, you get both the weasel and the mouses full trust then, as if feeding it, you hold the
weasel over the mouse. The mouse hesitates, grabs the weasel and they weirdly become
friends! This works for any other in the " make them bff" type of challenge. It also works
if you have a hesitant couple that wants to mate. Give the less confident one tto the big
one. That normally does it.

The weasel will eat mice, well basically anyhting thats small... And sometimes the mouse
may be friends with the wesel, depends on weasels mood. If the weasel wants to have babies
get a boy and girl both has to have one heart for u, after they has 1 heart drop them
together to 'bond' and when they are at 3 hearts for eachother they will mate.hope this
helps !!