One of my friends (JCV) inserted a little slip of paper into the gift envelope with this inscription:

illi non minus ac tibi
pectore uritur intimo
flamma, sed penite magis.

— Catullus, Wedding Song

I must admit, my Latin was nowhere near up to the task. But here is a translation:

A flame burns no less ardently in his innermost heart than in yours, but secretly, even more so.