I remember when he first starts to be all upset and whiny, he talks about meeting a bounty hunter in Ord Mantell or something, later on when he saves Luke he starts bragging about "man, you should have seen us at the south passage! She expressed her true feelings for me!"
But I think that was just about the talk they had in the Hoth Complex.
No secret planet of love making, sorry.
There is a comic about Han and Leia having a romantic night on Hoth, might be something for you..