How the Germans saw the Romans
Many of the Germanic tribes would have experienced the Romans as warlike, strange conquerors who invaded their traditional lands. They would have viewed them as alien oppressors, but only because their tribes were enemies of Rome. Others would have known the Romans much more closely, and would have perceived their civilization as superior or equal to their own. Many learned of Roman military efficiency, technological advancement and luxurious lifestyle. Especially the chieftains friendly to Rome attempted to assimilate among Roman nobles.
What the Romans thought of the Germans:
-brave and fierce individual warriors, but not good at team-work like the Romans
-generally uncivilized and hotheaded and unable to reason the same way Romans did
-inherently violent and quarrelsome, especially the males
-fond of drinking and generally engaging in vices. Before the introduction of Christianity, these “vices” were really anything involving unnecessary luxury, which both the Romans and Greeks viewed as contributing to the decline of civilization. Romans idealized moderation
-more independent of their husbands and fathers/brothers if they were women. We can’t know if this is true, as many images of “warrior women” were popularized by the Romans and Greeks (other examples being the Amazons), but Romans talked a lot about women also participating in traditionally male roles, like those of warriors
-lazy when it comes to everyday tasks like farmwork. The Romans liked to view themselves as a tough people, not just in battle, but also when it came to working hard. They viewed the German men as weak and lazy, because they left all the work to women and children. (This might actually have been a Germanic custom. Many Norsemen did the same in the Viking Age, but not out of laziness. They were fishing, trading or raiding, while the women and children worked in the fields)
-in some cases, unusually chaste. At least Julius Caesar refers to them as being especially dedicated to “hardship and fatigue.” He reports that it was considered a disgraceful to “know a woman” before one’s 20th birthday
-unusually large, physically speaking
-blue-eyed
-ruddy-haired
The Germans won the  Battle of the Teutoburg Forest, which was the first time the Germans won any battle against the Romans. This chaged everything. The Germans had their territory back. After that the roman empire collapsed