This letter asks your lover to take a trip with you.
1234, Main Street
Boston, MA 02123
07 April, 2005
<Recipient Address Goes Here>
I think we've come a long way in our relationship, wouldn't you? In the <time> we've been together, had so much fun and I've really come to think of you as the most important person in my life. So I have a suggestion: let's take a trip somewhere together.
I know, the easiest way to turn two lovers into two enemies is to put them in a situation where they have to be together all the time for weeks. But I think we can do it, and I think we'd have a wonderful time. I'd love to travel to <destination>, or any number of other places.
Let's talk it over and see if we can find the time and the money. If it all works out, I think we should go. I'm sure that we can keep from killing each other long enough to have a fantastic time. Let's talk about it soon.
encl: <List of enclosed items goes here>