Nothing suspicious. Depending on how much is given now and how much other gifts and inheritances nephew and partner have recieved, and from whom, they may have a liablity to CAT on the gift.
As charlie007 points out, you can give each of them €3,000 this year (and every year) and no CAT will arise. If you give either of them more than that there may be a CAT liablity, and you can't know whether there is or not without asking both of them quite a lot of personal questions.