String operation in single.php, acceptable?

I will be using a custom field to store a <b>string</b> containing
html image tags will addresses, for example:

“<img src=”love” /><img src=”me” /><img src=”now” />

it is acceptable to use a php explode operation in single.php?
in other words, perform an operation to divide the string into different peices?

The main question I’m asking here is, is it too much load on the server?

Thanks heaps.