Welcome to Bluelight amigo.
Ket is actually somewhat commonly used to cut MDMA pills. Although from what I understand the amount that is actually in the pill is nowhere near a proper oral dose to get any of the effects.
As per the combination, I've never done it but a lot of people seem to enjoy it.
Also, if you have any questions concerning a pill and its contents, you can look it up on pillreports.com. Just click the search button at the top of the page and go from there.
Stay safe,
-Thizzy
The word 'safe' is pretty subjective though - we dont know how you would react to either drug so nobody can tell you that its 'safe'.
Honestly though for your first experience try and have some friends around as its a great drug for social groups (large or small).
MDMA + Ket together is IMHO a great fun combination - and something I have taken alone a number of times.
One other thing to add - there hasnt been any MDMA+Ket swans reported so far, if your not testing then dont believe your dealer - they just want your money!