Summer. What in summer? Ice cream
When I worked at AVG, American colleagues came every summer day from lunch with an ice cream cone.
It cost about 70 crowns for 2 scoops, and I was saving such huge money (of course, lunch costs a hundred). However, after a month they still motivated me to take and try it.
What can I say - awesome.
For 70 crowns you'll get 2 huge tasty scoops. You can get more, you can get less. The cone crunches as it should. Who doesn't like cones - can take it in a paper cup.
In short, don't be stupid and definitely go when you're in Prague. No need to wander around expensive beer bars, make your girlfriend happy already.
The establishment is called "Angelato", angelato.cz
There are several of them in Prague, but I most often go near Old Town Square (at least there's something there, hooray).
PS everyone I tell gets hooked, believe what's written