Kathy Hilton Says Paris' Wedding Delay is Just Because She's Busy

Kathy Hilton says her daughter pushing back her wedding date is no cause for alarm ... and guess what -- when it goes down it ain't happening at a Hilton.

We got Paris' mom at LAX Wednesday afternoon ... she tells us Paris has been swamped promoting her new fragrance and skincare line, so she's got no time at all right now to tie the knot with Chris Zylka.

Kathy assures us she was with the couple recently and all's well -- no cold feet or prenup issues. Then again ... we're still not entirely sure Kathy knows what a prenuptial agreement is all about.

As we reported ... Paris and Chris got engaged at the beginning of the year, when he put a monstrous $2 million ring on her finger.

The couple's been open about some of their wedding plans -- including Chris revealing they have a prenup ... and Paris telling us who is and isn't on her guest list.

According to Kathy, whoever makes the final cut is just going to have to wait for the official invite ... when Paris gets more free time.