This would be cool. I don't know if it is possible but check out this link:
http://www.beatease.com/web-design.php/b2evo-change-the-read-more-text#more15

If you learn how, come back and tell us.

You could try changing the p tag to a span but I think there will still be issues...

Play around with the file in your skins folder called _item.content.inc.php

especially this bit at the top

// Default params:
$params = array_merge( array(
		'image_size'	     => 'fit-400x320',
		'before_url_link'  => '<p class="post_link">'.T_('Link:').' ',
		'after_url_link'   => '</p>',
		'before_more_link' => '<p class="bMore"> ',
		'after_more_link'  => ' ',
		'more_link_text'   => '#',
	), $params );

You could try changing <p class="bMore"> to a span class...

This does work BUT you must have Auto P switched off!!!

'before_more_link' => '<span class="bMore">',
		'after_more_link'  => '</span>',

This will allow you to have a text preamble to the "read more" link, as long as it's not wrapped in a p tag