When your partners Saturn is in your 3rd house it will play out as some sort of blockage when it comes to communicating and expressing yourselves.
Usually there are issues with the ability to speak openly and comfortably with one another. Sometimes it's seen as a language barrier between two people, other times one tends to over talk or cut off the other. There can be many misunderstandings as a result. It is usually the Saturn person that puts pressure on the house person or tries to grow the conversations up in a sense or keep the conversations short and to the point. Serious conversations surrounding business or convention might be main topics. The house person might feel fear surrounding expressing themselves or perhaps might withhold for fear of the Saturn person judging them. It may simply be that you both think quite differently, one of you may just talk to talk and the other might find themselves frustrated. Whatever the case Saturn always tries to get serious so in areas of communication you can expect some difficulty.