Well, if Saturn is in the 5th house, close to the cusp, it will powerfully aspect the 7th, 11th and 2nd house (according to Vedic aspects). There is a synergistic theme in all these houses: 5 is about love, 7 is about partnership, 11 is about pleasure and 2 is about family. So, Saturn placed near the cusp of the 5th house has a huge effect on romance.
Saturn’s effect is usually bad, though factors can make it less so, or even good. But the baseline interpretation would be that Saturn in this position would cause delays and grief to romance. If Saturn is in very good dignity and/or with very good aspects to it, and/or ruling important houses, then maybe it causes the relationships to be very few and not very sensual – but to have a deep, enduring, persisting, lasting quality to them.
Another effect of Saturn in the 5th house is to make the intellect more logical, analytical and critical (because Saturn represents logic, analysis, and criticism and the 5th house represents the intellect).
Another effect is problems with children.
One has to be very subtle when reading horoscopes, because something that is bad from one angle may be good from another. For example, I have Saturn in the 5th house, which seems a bit bad – especially in terms of romance or children. But since I am capricorn ascending, that Saturn is my 1st lord. The 1st lord in the 5th house is a very good placement – indicating intelligence, a loving nature, and closeness with children. So the two interpretations have to be reconciled. In my case I am very loving, yet have had very few romantic relationships, yet have a very deep, wonderful, persisting, lasting relationship with my excellent wife. My children are wonderful and I am very close to them, but they each have particular challenges, and also I tragically lost one of my children. This is an example of how to reconcile various interpretations.