My friend caught me looking at her boobs?

When girls are wearing loose shirts and bend down sometimes you can see their cleavage. Anyway one of my friends (cute but don't like her like that) saw me catching a peek. And I now she likes me because she keeps on smiling, bending down for extended periods of time, and flirting with me. I don't like her like that, she just has nice boobs, but how do I tell her that without sounding like a pig or hurting her feelings?
My friend caught me looking at her boobs?
Post Opinion