And easier to get a seat!

A week is not very long so I might not recommend 2 destinations. However, if you do go to both, remember that Sunday and Monday's most of France- uh...snoozes. Make those days in London just in case. (Yes, Paris is more cosmopolitan and all that, but why risk a lace being closed on the one day you are there?).

Have fun

a place...a place..

Not sure how you will book your flights, but if you could take off Friday afternoon from work, and catch an evening flight Friday night, so you get to London on Sat, you could use Sat afternoon to unwind, have Sun, Mon, Tue in London; then wed afternoon, and Thur, Fri & Sat in Paris.

Most of my flights to Europe have left in the evening and it works out fine. Even if you couldn't get off on Friday, a late night flight might still work.

I think you got old info from when Paris wasn't as clean and dog poo was abundant. And just in case you have heard that the French are nasty and rude...not true.

Paris is beautiful. London is edgier in some ways, but Paris is gorgeous and romantic. I love both, but Paris would be my primary destination. If you aren't really that interested in London, don't do both. So much to do and see in Paris and you won't see it all in a week.

Agree with previous post to fly in which ever city is cheaper and take the Eurostar to the other, if you decide to do both.

Exactly what denisea said.

Maybe your friends are confusing "old" with "dirty"? No large city is perfect, but Paris has my vote. No desire to return to London, whatsoever.