Of course with access to modern technology or other people, this would become trivial.
He could write it down and ask someone else without disabilities to read it to the blind man, or he could just send the blind man a message via SMS/Mail whatever, which can be processed text-to-speech.
If we assume there are only these three man and no access to special technology or other people (one could just place the riddle in a closed room in 16th century to assure this) there are two ways left - communication over a shared available sense (most likely touch) or by tricking the deaf man into telling the blind man.
The problem is for any kind of trick or secret language the blind and the mute man would have to share a secret-code or something, which has to be communicated first - and if we have a way to communicate that, we can just use this way for the vital information.
This leaves a trick where the deaf man will somehow reveal himself by accident (for example convincing him the blind man has left the room, he won't here when he comes back and talking to him about the kiss) or using violence or threats to persuade the perpetrator, which will be pretty hard, since the deaf man can tell the blind man anything and we cannot argue against it.
So the only ways left are conveying information by touch, morse, writing letters with somethimg the blind man can feel, or humming "he kissed your girl" ^^