There is only one URL for any wordpress.com blog. You can change the blog title if you wish at any time here > Settings > General but changing that blog title will not change the URL for the blog in question.
In the examples you use above clicking this URL http://lovecrear.wordpress.com cannot ever lead to http://anothername.wordpress.com and clicking this URL http://anothername.wordpress.com cannot ever lead to http://lovecrear.wordpress.com. However, if you wish visitors to click a link in the sidebar of one blog and arrive in the other blog then all you have to do is put the URLs of the opposite blog into a text widget and place it in the sidebars of the other blog, and visa versa.
If what you want to do is purchase a domain name and domain mapping please see here > http://en.support.wordpress.com/domain-mapping/
If what you want to do is move content from one wordpress.com blog to another wordpress.com blog then please see here > http://en.support.wordpress.com/moving-a-blog/
Would you please tell us exactly what it is that you want to achieve and why? If you do that then we may be able to come up with a way to achieve it.