Not necessarily. If he makes the payments directly, it's not deductible for
either of them:

I assumed he wasn't stupid enough to do that.


In the US, up to $250K in capital gain on the sale of one's principal
residence is exempt from capital gain taxes ($500K for a married couple
filing
jointly) provided that the taxpayer has used the home as his principal
residence for at least two years of

Everybody knows that.
Pat